Role of MoO3 as an anode buffer layer in organic photovoltaic cells

Abstract

Abstract:

Using molybdenum trioxide (MoO3) as anode buffer layer, organic photovoltaic (OPV) cells with a structure of ITO/MoO3/P3HT/C60/Bphen/Ag was studied. The effect of the thickness of MoO3 on electrical characteristics of the device was systematically investigated. From the conventional equivalent circuit model, the series resistance of the cell was calculated. Also, the absorption spectrum was measured by a spectrophotometer. The results indicate that at the optimized thickness of MoO3, the short circuit current, open circuit voltage and fill factor were all increased. The MoO3 layer plays an important role in forming good interface contact between anode and donor, which decreases the series resistance and improves the carrier transfer and collection efficiencies. Moreover, MoO3 has high optical transparency and can not decrease the photon absorption efficiency.

Key words: optoelectronics, organic photovoltaic cells, buffer layer, MoO3, interface modification

CLC Number:

O432.7

WANG Na-na, YU Jun-sheng, WANG Qi, SHAN Juan, JIANG Ya-dong . Role of MoO3 as an anode buffer layer in organic photovoltaic cells[J]. J4, 2011, 28(2): 191-196.

References

[1] Kim J Y, Lee K, Coates N E, Moses D, Nguyen T Q, Dante M, Heeger A J. Efficient tandem polymer solar cells fabricated by all-solution processing
[J]. Science, 2007, 317: 222-225.
[2] Yang Y, Wudl F. Organic Electronics: From Materials to Devices [J]. Adv. Mater., 2009, 21: 1401-1403.
[3] Kippelen B, Bredas J L. Organic photovoltaics [J]. Energy Environ. Sci., 2009, 2: 251-261.
[4] Huang J, Yu J S, Guan Z Q, Jiang Y D. Improvement in open circuit voltage of organic solar cells by inserting a thin phosphorescent iridium complex layer [J]. Appl. Phys. Lett., 2010, 97: 143301.
[5] Tang C W. Two-layer organic photovoltaic cell [J]. Appl. Phys. Lett., 1986, 48: 183-185.
[6] Chen H Y, Hou J H, Zhang S Q, Liang Y Y, Yang G W, Yang Y, Yu L P, Wu Y, Li G. Polymer solar cells with enhanced open-circuit voltage and efficiency [J]. Nature Photon., 2009, 3: 649-653.
[7] Liang Y Y, Xu Z, Xia J B, Tsai S T, Wu Y, Li G, Ray C, Yu L P. For the Bright Future-Bulk Heterojunction Polymer Solar Cells with Power Conversion Efficiency of 7.4 % [J]. Adv. Mater., 2010, 22: E135-E138.
[8] Heliatek and IAPP achieve production-relevant efficiency record for organic photovoltaic cells[OL]. http://www.heliatek.com/news-19.
[9] Sista S, Hong Z, Park M H, Xu Z, and Yang Y. High-Efficiency Polymer Tandem Solar Cells with Three-Terminal Structure [J]. Adv. Mater., 2009, 21: E1-E4.
[10] Wang N N, Yu J S, Zang Y, Huang J, Jiang Y D. Effect of buffer layers on the performance of organic photovoltaic cells based on copper phthalocyanine and C60 [J]. Sol. Energy Mater. Sol. Cells, 2010, 94: 263-266.
[11] Krebs F C, Gevorgyan S A, and Alstrup J. A roll-to-roll process to flexible polymer solar cells: model studies, manufacture and operational stability studies[J]. J. Mater. Chem., 2009, 19: 5442-5451.
[12] Feng Z H, Hou Y B, Lei D S. The influence of electrode buffer layers on the performance of polymer photovoltaic devices [J]. Renew. Energ., 2010, 35: 1175-1178.
[13] Godoy A, Cattin L, Toumi L, Diaz F R, del Valle M A, Soto G M, Kouskoussa B, Morsli M, Benchouk K, Khelil A, Bernede J C. Effects of the buffer layer inserted between the transparent conductive oxide anode and the organic electron donor [J]. Sol. Energy Mater. Sol. Cells, 2010, 94: 648-654.
[14] Shrotriya V, Li G, Yao Y, Chu C W, and Yang Y. Transition metal oxides as the buffer layer for polymer photovoltaic cells [J]. Appl. Phys. Lett., 2006, 88: 073508.
[15] Zhao D W, Liu P, Sun X W, Tan S T, Ke L, and Kyaw A K K. An inverted organic solar cell with an ultrathin Ca electron-transporting layer and MoO3 hole-transporting layer [J]. Appl. Phys. Lett., 2009, 95: 153304.
[16] Kinoshita Y, Takenaka R, Murata H. Independent control of open-circuit voltage of organic solar cells by changing film thickness of MoO3 buffer layer[J]. Appl. Phys. Lett., 2008, 92: 243309.
[17] Li N, Lassiter B E, Lunt R R, Wei G D, and Forrest S R. Open circuit voltage enhancement due to reduced dark current in small molecule photovoltaic cells[J]. Appl. Phys. Lett., 2009, 94: 023307.
[18] Yoo S, Domercq B, Kippelen B. Intensity-dependent equivalent circuit parameters of organic solar cells based on pentacene and C60 [J]. J. Appl. Phys., 2005, 97: 103706.
[19] Servaites J D, Yeganeh S, Marks T J, and Ratner M A. Efficiency Enhancement in Organic Photovoltaic Cells: Consequences of Optimizing Series Resistance[J]. Adv. Funct. Mater. 2010, 20: 97-104.
[20] Wang N N, Yu J S, Lin H, Jiang Y D. Organic photovoltaic cells with improved performance using bathophenanthroline as a buffer layer[J]. Chin. J. Chem. Phys., 2010, 23: 84-88.
[21] Huang J, Yu J S, Lin H, Jiang Y D. Detailed analysis of bathocuproine layer for organic solar cells based on copper phthalocyanine and C60 [J]. J. Appl. Phys., 2009, 105: 073105.