TY - JOUR AU - Park, Joo Hyung AU - Jo, Yonghee AU - Cho, Ara AU - Jeong, Inyoung AU - An, Jin Gi AU - Kim, Kihwan AU - Ahn, Seung Kyu AU - Shin, Donghyeop AU - Cho, Jun-Sik PY - 2025 TI - Enhancement of Cd-Free All-Dry-Processed Cu(In1-x,Gax)Se2 Thin-Film Solar Cells by Simultaneous Adoption of an Enlarged Bandgap Absorber and Tunable Bandgap Zn1-xMgxO Buffer JO - Energy & Environmental Materials SN - 2575-0348 VL - 8 IS - 1 AB - Attempts to remove environmentally harmful materials in mass production industries are always a major issue and draw attention if the substitution guarantees a chance to lower fabrication cost and to improve device performance, as in a wide bandgap Zn1-xMgxO (ZMO) to replace the CdS buffer in Cu(In1-x,Gax)Se2 (CIGSe) thin-film solar cell structure. ZMO is one of the candidates for the buffer material in CIGSe thin-film solar cells with a wide and controllable bandgap depending on the Mg content, which can be helpful in attaining a suitable conduction band offset. Hence, compared to the fixed and limited bandgap of a CdS buffer, a ZMO buffer may provide advantages in Voc and Jsc based on its controllable and wide bandgap, even with a relatively wider bandgap CIGSe thin-film solar cell. In addition, to solve problems with the defect sites at the ZMO/CIGSe junction interface, a few-nanometer ZnS layer is employed for heterojunction interface passivation, forming a ZMO/ZnS buffer structure by atomic layer deposition (ALD). Finally, a Cd-free all-dry-processed CIGSe solar cell with a wider bandgap (1.25 eV) and ALD-grown buffer structure exhibited the best power conversion efficiency of 19.1%, which exhibited a higher performance than the CdS counterpart. UR - https://doi.org/10.1002/eem2.12796 DO - 10.1002/eem2.12796