A comparative study on charge carrier recombination across the junction region of Cu2ZnSn(S,Se)4 and Cu(In,Ga)Se2 thin film solar cells

• Published in: AIP advances Vol. 6; no. 3; pp. 035216 - 035216-8
• Main Authors: Halim, Mohammad Abdul, Islam, Muhammad Monirul, Luo, Xianjia, Sakurai, Takeaki, Sakai, Noriyuki, Kato, Takuya, Sugimoto, Hiroki, Tampo, Hitoshi, Shibata, Hajime, Niki, Shigeru, Akimoto, Katsuhiro
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 01.03.2016; AIP Publishing LLC
• Subjects: Bias; Carrier recombination; Comparative studies; Copper indium gallium selenides; Current carriers; Decay; Electroluminescence; Photoluminescence; Photovoltaic cells; Radiative recombination; Selenides; Separation; Solar cells; Temperature dependence; Thin films; Time dependence
• ISSN: 2158-3226; 2158-3226
• DOI: 10.1063/1.4944911

A comparative study with focusing on carrier recombination properties in Cu2ZnSn(S,Se)4 (CZTSSe) and the CuInGaSe2 (CIGS) solar cells has been carried out. For this purpose, electroluminescence (EL) and also bias-dependent time resolved photoluminescence (TRPL) using femtosecond (fs) laser source were performed. For the similar forward current density, the EL-intensity of the CZTSSe sample was obtained significantly lower than that of the CIGS sample. Primarily, it can be attributed to the existence of excess amount of non-radiative recombination center in the CZTSSe, and/or CZTSSe/CdS interface comparing to that of CIGS sample. In case of CIGS sample, TRPL decay time was found to increase with the application of forward-bias. This can be attributed to the reduced charge separation rate resulting from the reduced electric-field at the junction. However, in CZTSSe sample, TRPL decay time has been found almost independent under the forward and reverse-bias conditions. This phenomenon indicates that the charge recombination rate strongly dominates over the charge separation rate across the junction of the CZTSSe sample. Finally, temperature dependent V OC suggests that interface related recombination in the CZTSSe solar cell structure might be one of the major factors that affect EL-intensity and also, TRPL decay curves.