Influence of Ga content on defects in CuInxGa1−xSe2 based solar cell absorbers investigated by sub gap modulated photocurrent and admittance spectroscopy

Jaafar Serhan (1) , Zakaria Djebbour (1) , Denis Mencaraglia (1) , F. Couzinié-Devy (2) , Nicolas Barreau (2) , John Kessler (2)

1 LGEP - Laboratoire de génie électrique de Paris
2 IMN - Institut des Matériaux Jean Rouxel

In this work, we investigate the influence of gallium content on the defects properties of co-evaporated CuInxGa1 − xSe2 by subgapmodulatedphotocurrentspectroscopy and admittancespectroscopy techniques. A series of CuInxGa1 − xSe2basedsolarcells with different gallium content in the range from 0% to 33%, and with the same CdS buffer layer have been investigated. On one hand, photocurrentspectroscopy results show 2 types of defects named D1 and D2, and on the other hand, admittancespectroscopy results exhibit only one type of defect. I-V curves show that one of the two defects probed by photocurrent is responsible of the dominant recombination mechanisms next to the heterointerface, between the absorber and the buffer layers. Moreover, I-V curves under AM 1.5 conditions show that the cell with no probed D2 defect presents the best photovoltaic performances.

Jaafar Serhan, Zakaria Djebbour, Denis Mencaraglia, F. Couzinié-Devy, Nicolas Barreau, et al.. Influence of Ga content on defects in CuInxGa1−xSe2 based solar cell absorbers investigated by sub gap modulated photocurrent and admittance spectroscopy. Thin Solid Films, 2011, 519 (21), pp.7312-7316. ⟨10.1016/j.tsf.2011.01.095⟩. ⟨hal-00710731⟩