[23a-E106-1~11] 13.9 Compound solar cells

▲ [23a-E106-2] Impact of quasi-fermi level splitting and sub-bandgap absorptivity on the V_OC loss in
CIGS solar cells

〇(D)Hamidou Tangara¹, Yulu He¹, Muhammad Monirul Islam¹, Shogo Ishizuka², Takeaki Sakurai¹ (1.Univ.Tsukuba, 2.AIST)

Keywords:CIGS solar cells, Quasi-fermi level splitting, Open-circuit voltage loss

The Shockley and Queisser principle of detailed balance (SQ model) between absorbed and emitted radiative fluxes from a photovoltaic absorber is the most common method used to evaluate the loss mechanisms in solar cells. The model assumed a step-like absorption coefficient thus neglecting the effect of band tailing for material with non-abrupt band edges wherein the electron-hole quasi fermi level splitting (QFLS) can modify both the absorption and emission spectrum. Here, we analyze the impact of the QFLS and sub-bandgap absorptivity on the V_OC loss mechanism in CIGS solar cell devices using full-spectrum fitting of the photoluminescence (PL) emission.