Increase in Open-circuit Voltage and Improved Stability of Organic Solar Cells by Inserting a Molybdenum Trioxide Buffer Layer

2009 ◽  
Vol 1154 ◽  
Author(s):  
Hideyuki Murata ◽  
Yoshiki Kinoshita ◽  
Yoshihiro Kanai ◽  
Toshinori Matsushima ◽  
Yuya Ishii

AbstractWe report the increase in open-circuit voltage (Voc) by inserting of MoO3 layer on ITO substrate to improve built-in potential of organic solar cells (OSCs). In the OSCs using 5,10,15,20-tetraphenylporphyrine (H2TPP) as a p-type material and C60 as a n-type material, the Voc effectively increased from 0.57 to 0.97 V as increasing MoO3 thickness. The obtained highest Voc (0.97 V) is consistent with the theoretical value estimated from the energy difference between the LUMO (−4.50 eV) of C60 and the HOMO (−5.50 eV) of H2TPP layer. Importantly, the enhancement in the Voc was achieved without affecting the short-circuit current density (Jsc) and the fill-factor (FF). Thus, the power conversion efficiency of the device linearly increased from 1.24% to 1.88%. We also demonstrated that a MoO3 buffer layer enhances the stability of OSCs after photo-irradiation. We have investigated the stability of OSCs using H2TPP and N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine as a p-type layer. The both devices with MoO3 layer showed improved stability. These results clearly suggest that the interface at ITO/p-type layer affects the device stability.

2007 ◽  
Vol 1012 ◽  
Author(s):  
Raquel Caballero ◽  
Susanne Siebentritt ◽  
Christian A. Kaufmann ◽  
Carola Kelch ◽  
Daniel Schweigert ◽  
...  

AbstractThe objective of this work is to increase the open circuit voltage of CuGaSe2(CGS)-based solar cells without decreasing their efficiency. For that, the interface between the p-type CGS absorber and the n-type CdS/ZnO window layer is compared using three different recipes for the growth of the buffer layer. Results show the importance of the adaptation of the CdS buffer layer to the CuGaSe2 absorber film. A maximum open circuit voltage of 922 mV is achieved for the devices when using 60ºC as the chemical bath temperature and a low thiourea concentration. Drive-level capacitance profiling, external quantum efficiency and temperature dependent current-voltage measurements reveal a better quality of the CdS/CuGaSe2 interface for this buffer layer deposition conditions. Factors such as the larger depletion region width and the lower doping level, reducing the tunnelling component, are pointed out as responsible of the higher Voc.


2003 ◽  
Vol 762 ◽  
Author(s):  
Jianhua Zhu ◽  
Vikram L. Dalal

AbstractWe report on the growth and properties of microcrystalline Si:H and (Si,Ge):H solar cells on stainless steel substrates. The solar cells were grown using a remote, low pressure ECR plasma system. In order to crystallize (Si,Ge), much higher hydrogen dilution (∼40:1) had to be used compared to the case for mc-Si:H, where a dilution of 10:1 was adequate for crystallization. The solar cell structure was of the p+nn+ type, with light entering the p+ layer. It was found that it was advantageous to use a thin a-Si:H buffer layer at the back of the cells in order to reduce shunt density and improve the performance of the cells. A graded gap buffer layer was used at the p+n interface so as to improve the open-circuit voltage and fill factor. The open circuit voltage and fill factor decreased as the Ge content increased. Quantum efficiency measurements indicated that the device was indeed microcrystalline and followed the absorption characteristics of crystalline ( Si,Ge). As the Ge content increased, quantum efficiency in the infrared increased. X-ray measurements of films indicated grain sizes of ∼ 10nm. EDAX measurements were used to measure the Ge content in the films and devices. Capacitance measurements at low frequencies ( ~100 Hz and 1 kHz) indicated that the base layer was indeed behaving as a crystalline material, with classical C(V) curves. The defect density varied between 1x1016 to 2x1017/cm3, with higher defects indicated as the Ge concentration increased.


2019 ◽  
Vol 115 (15) ◽  
pp. 153301 ◽  
Author(s):  
Seiichiro Izawa ◽  
Naoto Shintaku ◽  
Mitsuru Kikuchi ◽  
Masahiro Hiramoto

2010 ◽  
Vol 94 (12) ◽  
pp. 2332-2336 ◽  
Author(s):  
Sun-Young Park ◽  
Hye-Ri Kim ◽  
Yong-Jin Kang ◽  
Dong-Ho Kim ◽  
Jae-Wook Kang

RSC Advances ◽  
2015 ◽  
Vol 5 (79) ◽  
pp. 64724-64730 ◽  
Author(s):  
Derya Baran ◽  
Sule Erten-Ela ◽  
Andreas Kratzer ◽  
Tayebeh Ameri ◽  
Christoph J. Brabec ◽  
...  

In this work, a bis-adduct C60 derivative was facilely synthesized using an alkyl solubilizing group. This semiconductor offers a higher LUMO level compared to PCBM, which resulted in a significantly enhanced Voc of 0.73 V in organic solar cells.


2014 ◽  
Vol 14 (4) ◽  
pp. 434-439 ◽  
Author(s):  
Carl Poelking ◽  
Max Tietze ◽  
Chris Elschner ◽  
Selina Olthof ◽  
Dirk Hertel ◽  
...  

2015 ◽  
Vol 5 (6) ◽  
pp. 1757-1761 ◽  
Author(s):  
Daniel Amkreutz ◽  
William D. Barker ◽  
Sven Kuhnapfel ◽  
Paul Sonntag ◽  
Onno Gabriel ◽  
...  

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