Name: printing fabrication of bulk heterojunction solar cells and in situ morphology characterization
Uploaded: 2017-01-29T14:00:00
Description: Watch this Scientific Journal Video about Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization at JoVE.com

This work was supported by Polymer-Based Materials for Harvesting Solar Energy (PHaSE), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Basic Energy Sciences under award number DE-SC0001087 and the U.S. Office of Naval Research under contract N00014-15-1-2244. Portions of this research were carried out at beamline 7.3.3 and 11.0.1.2 at the Advanced Light Source, Lawrence Berkeley National Laboratory, which was supported by the DOE, Office of Science, and Office of Basic Energy Sciences.

1. Photon-active Blend Ink Preparation
<ol>
	<li>Weigh 10 mg of DPPBT polymer and 10 mg of PC71BM material (chemical structures shown in Figure 1). Mix them in a 4 ml vial.</li>
	<li>Add 1.5 ml chloroform and 75 &#181;l of 1,2-dichlorobenzene into the mixture.</li>
	<li>Put a small stir bar into the vial, close the vial with a polytetrafluoroethylene (PTFE) cap, and transfer the vial to a hot plate. Stir at ~400 rpm, and heat at ~50 &#176;C overnight before use.</li>
</ol>
<p class="jove_tit...

<ol>
	<li>Brabec, C. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymer-Fullerene+Bulk-Heterojunction+Solar+Cells.">Polymer-Fullerene Bulk-Heterojunction Solar Cells.</a> Adv. Mater. 22 (34), 3839-3856 (2010).</li><li>Thompson, B. C., Fr&#233;chet, J. M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymer-Fullerene+Composite+Solar+Cells.">Polymer-Fullerene Composite Solar Cells.</a> Angew. Chem. Int. Ed. 47 (1), 58-77 (2008).</li><li>G&#252;nes, S., Neugebauer, H., Sariciftci, N. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conjugated+Polymer-Based+Organic+Solar+Cells.">Conjugated Polymer-Based Organic Solar Cells.</a> Chem. Rev. 107 (4), 1324-1338 (2007).</li><li>Krebs, F. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+OE-A+OPV+demonstrator+anno+domini+2011.">The OE-A OPV demonstrator anno domini 2011.</a> Energy Environ. Sci. 4 (10), 4116 (2011).</li><li>Krebs, F. C., Tromholt, T., J&#248;rgensen, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Upscaling+of+polymer+solar+cell+fabrication+using+full+roll-to-roll+processing.">Upscaling of polymer solar cell fabrication using full roll-to-roll processing.</a> Nanoscale. 2 (6), 873 (2010).</li><li>Liu, F., Gu, Y., Jung, J. W., Jo, W. H., Russell, T. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+morphology+of+polymer-based+photovoltaics.">On the morphology of polymer-based photovoltaics.</a> J. Polym. Sci. Polym. Phy. 50 (15), 1018-1044 (2012).</li><li>Liu, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+the+morphology+of+solution-processed+bulk+heterojunction+organic+photovoltaics.">Characterization of the morphology of solution-processed bulk heterojunction organic photovoltaics.</a> Prog. Polym. Sci. 38 (12), 1990-2052 (2013).</li><li>Schmidt-Hansberg, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+monitoring+the+drying+kinetics+of+knife+coated+polymer-fullerene+films+for+organic+solar+cells.">In situ monitoring the drying kinetics of knife coated polymer-fullerene films for organic solar cells.</a> J. appl. phys. 106 (12), 124501 (2009).</li><li>Pearson, A. J., Wang, T., Lidzey, D. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+dynamic+measurements+in+correlating+structure+with+optoelectronic+properties+in+polymer+fullerene+bulk-heterojunction+solar+cells.">The role of dynamic measurements in correlating structure with optoelectronic properties in polymer fullerene bulk-heterojunction solar cells.</a> Rep. Prog. Phys. 76 (2), 022501 (2013).</li><li>Treat, N. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interdiffusion+of+PCBM+and+P3HT+Reveals+Miscibility+in+a+Photovoltaically+Active+Blend.">Interdiffusion of PCBM and P3HT Reveals Miscibility in a Photovoltaically Active Blend.</a> Adv. Energy Mater. 1 (1), 82-89 (2010).</li><li>Collins, B. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+Miscibility+of+Polymer-Fullerene+Blends.">Molecular Miscibility of Polymer-Fullerene Blends.</a> J. Phys. Chem. Lett. 1 (21), 3160-3166 (2010).</li><li>Chen, D., Liu, F., Wang, C., Nakahara, A., Russell, T. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bulk+Heterojunction+Photovoltaic+Active+Layers+via+Bilayer+Interdiffusion.">Bulk Heterojunction Photovoltaic Active Layers via Bilayer Interdiffusion.</a> Nano Lett. 11 (5), 2071-2078 (2011).</li><li>Gu, Y., Wang, C., Russell, T. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multi-Length-Scale+Morphologies+in+PCPDTBT/PCBM+Bulk-Heterojunction+Solar+Cells.">Multi-Length-Scale Morphologies in PCPDTBT/PCBM Bulk-Heterojunction Solar Cells.</a> Adv. Energy Mater. 2 (6), 683-690 (2012).</li><li>Perez, L. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solvent+Additive+Effects+on+Small+Molecule+Crystallization+in+Bulk+Heterojunction+Solar+Cells+Probed+During+Spin+Casting.">Solvent Additive Effects on Small Molecule Crystallization in Bulk Heterojunction Solar Cells Probed During Spin Casting.</a> Adv. Mater. 25 (44), 6380-6384 (2013).</li><li>Lee, J. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Processing+Additives+for+Improved+Efficiency+from+Bulk+Heterojunction+Solar+Cells.">Processing Additives for Improved Efficiency from Bulk Heterojunction Solar Cells.</a> J. Am. Chem. Soc. 130 (11), 3619-3623 (2008).</li><li>Shin, N., Richter, L. J., Herzing, A. A., Kline, R. J., DeLongchamp, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+Processing+Additives+on+the+Solidification+of+Blade-Coated+Polymer/Fullerene+Blend+Films+via+In-Situ+Structure+Measurements.">Effect of Processing Additives on the Solidification of Blade-Coated Polymer/Fullerene Blend Films via In-Situ Structure Measurements.</a> Adv. Energy Mater. 3 (7), 938-948 (2013).</li><li>S&#0248;dergaard, R., H&#246;sel, M., Angmo, D., Larsen-Olsen, T. T., Krebs, F. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Roll-to-roll+fabrication+of+polymer+solar+cells.">Roll-to-roll fabrication of polymer solar cells.</a> Mater. Today. 15 (1-2), 36-49 (2012).</li><li>Liu, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+Polymer+Solar+Cells+Based+on+a+Low+Bandgap+Semi-crystalline+DPP+Polymer-PCBM+Blends.">Efficient Polymer Solar Cells Based on a Low Bandgap Semi-crystalline DPP Polymer-PCBM Blends.</a> Adv. Mater. 24 (29), 3947-3951 (2012).</li><li>Liu, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Relating+Chemical+Structure+to+Device+Performance+via+Morphology+Control+in+Diketopyrrolopyrrole-Based+Low+Band+Gap+Polymers.">Relating Chemical Structure to Device Performance via Morphology Control in Diketopyrrolopyrrole-Based Low Band Gap Polymers.</a> J. Am. Chem. Soc. 135 (51), 19248-19259 (2013).</li><li>Liu, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fast+Printing+and+In+Situ+Morphology+Observation+of+Organic+Photovoltaics+Using+Slot-Die+Coating.">Fast Printing and In Situ Morphology Observation of Organic Photovoltaics Using Slot-Die Coating.</a> Adv. Mater. 27 (5), 886-891 (2015).</li></ol>

The method described here focuses on developing a film preparation method that can be easily scaled up in industrial production. Thin film printing and synchrotron morphology characterization are the most critical steps with the protocol. In previous lab scaled OPV research, spin coating is used as the dominant method to fabricate thin film devices. However, this process uses high centrifuge force to spread out BHJ solution, which is quite different from industrial based roll-to-roll fabrication. Thus the knowledge and e...

Organic photovoltaics (OPV) are a promising technology to produce cost-effective renewable energies in the near future.1,2,3 Tremendous efforts have been made to develop photo-active polymers and fabricate high efficiency devices. To date, single layered OPV devices have achieved a &#62;10% power conversion efficiency (PCE). These efficiencies have been achieved on laboratory scale devices using spin coating to generate the film, and translation to larger size scale devices has been fraught with significant reductions in the PCE.4,5 In industry, roll-to-roll (R2R) based thin film coating is used to generate photon active thin films on conductive substrates, which is quite different from typical laboratory-scale processes, particularly in the rate of solvent removal. This is critical since the morphologies are kinetically trapped, resulting from the interplay between multiple kinetic processes, including phase separation, ordering, orientation and solvent evaporation.6,7 This kinetically trapped morphology, though, largely determines the performance of the solar cell devices. Thus, understanding the development of the morphology during the coating process is of high importance for manipulating the morphology so as to optimize performance.
The optimization of the morphology requires understanding the kinetics associated with the ordering of the hole-conducting polymer in solution as solvent is removed;8,9 quantifying the interactions of the polymer with the fullerene-based electron conductor;10,11,12 understanding the roles of additives in defining the morphology;13,14,15 and balancing the relative rates of evaporation of the solvent(s) and additives.16 It has been a challenge to characterize the evolution of the morphology quantitatively in the active layer in an industrially relevant setting. Roll-to-roll processing has been studied for the fabrication of large scale OPV devices.4,17 However, these studies were performed in a manufacturing setting where large quantities of materials are used, effectively limiting studies to commercially available polymers.
In this paper, the technical details of fabricating OPV devices using a mini-slot die coating system are demonstrated. Coating parameters such as film drying kinetics and film thickness control are applicable to larger scale processes, making this study directly related to industry fabrication. Besides, a very small amount of material is used in the mini slot die coating experiment, making this processing applicable to new synthetic materials. In design, this mini-slot die coater can be mounted onto synchrotron end stations, and thus grazing incidence small angle X-ray scattering (GISAXS) and X-ray diffraction (GIXD) can be used to enable real-time studies on the evolution of the morphology over a wide range of length scales at different stages of the film drying process under a range of processing conditions. Information obtained in these studies can be directly transferred to an industrial manufacturing setting. The small amount of materials used enables a rapid screening of a large number of photo-active materials and their mixtures under various processing conditions.
The semi-crystalline diketopyrrolopyrrole and quaterthiophene (DPPBT) based low band conjugated polymer is used as the model donor material, and (6,6)-phenyl C71-butyric acid methyl ester (PC71BM) is used as the electronic acceptor.18,19 It is shown in previous studies that DPPBT:PC71BM blends form large size phase separation when using chloroform as the solvent. A chloroform:1,2-dichlorobenzene solvent mixture can reduce the size of phase separation and thus increase the device performance. The morphology formation during the solvent drying process is investigated in situ by grazing incidence X-ray diffraction and scattering. Solar cell devices fabricated using the mini-slot die coater showed an average PCE of 5.2% using the best solvent mixture conditions,20 which is similar to spin-coating fabricated devices. The mini-slot die coater opens a new route to fabricate solar cell devices in a research laboratory setting that mimics an industrial process, filling a gap in the predicting the viability of these materials in an industrially relevant setting.

<table border="0" cellpadding="0" cellspacing="0" width="787">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">PC71BM</td>
			<td style="width:263px;">Nano-C Inc</td>
			<td style="width:184px;">nano-c-PCBM-SF</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">DPPBT</td>
			<td style="width:263px;">The University of Massachusetts</td>
			<td style="width:184px;">Custom Made</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">PEDOT:PSS</td>
			<td style="width:263px;">Heraeus</td>
			<td style="width:184px;">P VP Al 4083</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Mucasol Liquid Cleaner</td>
			<td style="width:263px;">Sigma-Aldrich</td>
			<td style="width:184px;">Z637181</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Acetone</td>
			<td style="width:263px;">Sigma-Aldrich</td>
			<td style="width:184px;">270725</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Isopropyl Alcohol</td>
			<td style="width:263px;">BDH</td>
			<td style="width:184px;">BDH1133</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Chloroform</td>
			<td style="width:263px;">Sigma-Aldrich</td>
			<td style="width:184px;">372978&#160;</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">1,2-diChlorobenzene</td>
			<td style="width:263px;">Sigma-Aldrich</td>
			<td style="width:184px;">240664</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Lithium fluoride</td>
			<td style="width:263px;">Sigma-Aldrich</td>
			<td style="width:184px;">669431</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Aluminum</td>
			<td style="width:263px;">Kurt Lesker</td>
			<td style="width:184px;">EVMAL50QXHD</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Glass vials</td>
			<td style="width:263px;">Fisher Scientific</td>
			<td style="width:184px;">03-391-7B</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Ultrasonic Cleaner</td>
			<td style="width:263px;">Cleanosonic</td>
			<td style="width:184px;">Branson 2800</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Oven</td>
			<td style="width:263px;">WVR</td>
			<td style="width:184px;">414005-118</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Cleaning Rack</td>
			<td style="width:263px;">Lawrence Berkeley National Lab</td>
			<td style="width:184px;">Custom Made</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Shadow Mask</td>
			<td style="width:263px;">Lawrence Berkeley National Lab</td>
			<td style="width:184px;">Custom Made</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">UV-Ozone Cleaner</td>
			<td style="width:263px;">UVOCS INC</td>
			<td style="width:184px;">T16X16 OES</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Glove Box</td>
			<td style="width:263px;">MBraun</td>
			<td style="width:184px;">Custom Made</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Evaporator</td>
			<td style="width:263px;">MBraun</td>
			<td style="width:184px;">Custom Made</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Slot Die Coater</td>
			<td style="width:263px;">Jema Science Inc</td>
			<td style="width:184px;">Custom Made</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Solar Simulator</td>
			<td style="width:263px;">Newport</td>
			<td style="width:184px;">Class ABB</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Spin Coater</td>
			<td style="width:263px;">SCS Equipment</td>
			<td style="width:184px;">SCS G3</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">Hot Plate</td>
			<td style="width:263px;">Thermo Scientific</td>
			<td style="width:184px;">SP131015Q</td>
			<td style="width:149px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:191px;">X-ray Measurement</td>
			<td style="width:263px;">Lawrence Berkeley National Lab</td>
			<td style="width:184px;">Beamline 7.3.3</td>
			<td style="width:149px;"></td>
		</tr>
	</tbody>
</table>

printing fabrication of bulk heterojunction solar cells and in situ morphology characterization

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices have used devices prepared by spin coating, a process that is not amenable to large-scale fabrication. This mismatch in device fabrication makes it difficult to translate quantitative results obtained in the laboratory to the commercial level, making optimization difficult. Using a mini-slot die coater, this mismatch can be resolved by translating the commercial process to the laboratory and characterizing the structure formation in the active layer of the device in real time and in situ as films are coated onto a substrate. The evolution of the morphology was characterized under different conditions, allowing us to propose a mechanism by which the structures form and grow. This mini-slot die coater offers a simple, convenient, material efficient route by which the morphology in the active layer can be optimized under industrially relevant conditions. The goal of this protocol is to show experimental details of how a solar cell device is fabricated using a mini-slot die coater and technical details of running in situ structure characterization using the mini-slot die coater.

Shown in Figure 3 is the mini-slot die coating system. It consists of one coating machine, one syringe pump and a central control box. The coating machine is the essential part, which is made of a slot die head, one horizontal translational stage, and one vertical translational stage. The slot die head is mounted to the base of a vertical translational motor through a 2-D tilting manipulator. Figure 10a shows the printer main body without mounting the pri...

Watch this Scientific Journal Video about Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization at JoVE.com

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Here, we present a protocol to fabricate organic thin film solar cells using a mini-slot die coater and related in-line structure characterizations using synchrotron scattering techniques.

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices ...

Research

Education

JoVE Core

JoVE Journal

Biology

Engineering

Cellular Processes

Photosynthesis

SCIENTISTS IN ACTION

Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities

Slow light has been one of the hot topics in the photonics community in the past decade, generating great interest both from a fundamental point of view ...

Integration of Light Trapping Silver Nanostructures in Hydrogenated Microcrystalline Silicon Solar Cells by Transfer Printing

One of the potential applications of metal nanostructures is light trapping in solar cells, where unique optical properties of nanosized metals, commonly ...

Fabrication and Operation of Acoustofluidic Devices Supporting Bulk Acoustic Standing Waves for Sheathless Focusing of Particles

Acoustophoresis refers to the displacement of suspended objects in response to directional forces from sound energy. Given that the suspended objects must ...

Fabrication and Characterization of Superconducting Resonators

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors ...

Digital Printing of Titanium Dioxide for Dye Sensitized Solar Cells

Silicon solar cell manufacturing is an expensive and high energy consuming process. In contrast, dye sensitized solar cell production is less ...

Morphology Control for Fully Printable Organic&#8211;Inorganic Bulk-heterojunction Solar Cells Based on a Ti-alkoxide and Semiconducting Polymer

Morphology Control for Fully Printable OrganicÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â‚¬Å¡Ã‚Â¬ÃƒÂ¢Ã¢â€šÂ¬Ã…â€œInorganic Bulk-heterojunction Solar Cells Based on a Ti-alkoxide and Semiconducting Polymer

The photoactive layer of a typical organic thin-film bulk-heterojunction (BHJ) solar cell commonly uses fullerene derivatives as the electron-accepting ...

Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells

Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells

Here, we demonstrate the incorporation of monovalent cation additives into CH3NH3PbI3 perovskite in order to adjust the optical, excitonic, and electrical ...

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

Electrically assisted deformation (EAD) is increasingly being used to improve the formability of metals during processes such as sheet metal rolling and ...

In Situ Monitoring of the Accelerated Performance Degradation of Solar Cells and Modules: A Case Study for Cu(In,Ga)Se2 Solar Cells

In Situ Monitoring of the Accelerated Performance Degradation of Solar Cells and Modules: A Case Study for CuIn,GaSe2 Solar Cells

The levelized cost of electricity (LCOE) of photovoltaic (PV) systems is determined by, among other factors, the PV module reliability. Better prediction ...

Developing High Performance GaP/Si Heterojunction Solar Cells

To improve the efficiency of Si-based solar cells beyond their Shockley-Queisser limit, the optimal path is to integrate them with III-V-based solar ...