Yu, Hyeonggeun Choi, Eun Pyung Chai, Sung Uk Lee, Sang hyo Park, Ha Kyung Kim, Gee Yeong Jo, William Kim, Won Mok Kim, Donghwan Joo, Byoungkwon Min, Byoung Koun Jeong, Jeung-hyun 2024-01-19T09:33:18Z 2024-01-19T09:33:18Z 2023-04-13 2023-05 https://pubs.kist.re.kr/handle/201004/113770 The recent efficiency boosting of Cu(In,Ga)Se-2 (CIGS) solar cells is undoubtedly triggered by heavy alkali postdeposition treatments (PDTs). However, the effects are not obvious under monolithically integrated CIGS modules where various current-shunting sources can deteriorate the device performance. Herein, It is reported that KF PDT can effectively suppress the major shunting sources caused by P1 and P3 laser scribing for monolithic interconnection, reducing the cell-to-module (CTM) efficiency gap in CIGS photovoltaics. CIGS with NaF PDT exhibits nearly isotropic and high hole mobilities, causing a large CTM efficiency loss. CIGS with additional KF PDT, on the other hand, reveals much lower in-plane hole mobility than the out-of-plane component, significantly increasing the P1 shunt resistance without exacerbating the photocarrier extraction in the active area. It is suggested that such anisotropic charge transport is due to carrier scattering by low-conductivity phases at the CIGS grain boundaries. Furthermore, passivation of the front junction by KF PDT raises the tolerance to P3 scribing-induced damage, increasing the P3 shunt resistance while preserving the junction property unlike the NaF PDT case. The work implies that the recent trend of employing heavy alkali PDTs for a high-efficiency cell is also crucial for designing a high-efficiency CIGS module. English WILEY-V C H VERLAG GMBH Anisotropic Charge Transport in Cu(In,Ga)Se-2 by Heavy Alkali Postdeposition Treatment for Reducing Cell-to-Module Efficiency Loss in Monolithically Integrated Photovoltaic Modules Article 10.1002/solr.202300055 1 Solar RRL, v.7, no.10 Solar RRL 7 10 Y scie scopus 000956575600001 2-s2.0-85150821123 Energy & Fuels Materials Science, Multidisciplinary Energy & Fuels Materials Science Article SOLAR-CELLS ABSORBERS GAP Cu(In Ga)Se-2 (CIGS) heavy alkali postdeposition treatment (PDT) photovoltaic modules shunt resistance