Kim, Byungwoo Park, Gi Soon Hwang, Yun Jeong Won, Da Hye Kim, Woong Lee, Dong Ki Min, Byoung Koun 2024-01-19T18:33:45Z 2024-01-19T18:33:45Z 2021-09-05 2019-12 2380-8195 https://pubs.kist.re.kr/handle/201004/119270 As CuInGa-based chalcopyrite photocathodes suffer from poor hydrogen evolution activity, n-type overlayers and hydrogen evolution catalysts (HECs) need to be deposited on the film surface to drive surface band bending and reduce the overpotential for the hydrogen evolution reaction (HER). Here, we present a Cu(In,Ga)(S,Se)(2) (CIGSSe) photocathode with grown-in CuxS HECs enabling solar water splitting without the deposition of additional n-type overlayers and HECs. The controlled two-step chalcogenization using a Cu-rich CuInGa precursor film resulted in the natural formation of the CuxS phase at the CIGSSe film surface and an increase in S content by substituting Se. Electrochemical water reduction tests elucidated that the naturally formed CuxS alters the surface state of CIGSSe and reduces the overpotential for HER Also, the S incorporation allows fine-tuning to make the CIGSSe band gap favorable for solar water splitting. Consequently, the CIGSSe photocathode showed -25.7 mA.cm(-2) photocurrent density and 3 h photostability for photoelectrochemical hydrogen evolution. English AMER CHEMICAL SOC HYDROGEN EVOLUTION CHALCOPYRITE FILMS CDS REDUCTION CELLS LAYER Cu(In,Ga)(S,Se)(2) Photocathodes with a Grown-In CuxS Catalyst for Solar Water Splitting Article 10.1021/acsenergylett.9b01816 1 ACS ENERGY LETTERS, v.4, no.12, pp.2937 - 2944 ACS ENERGY LETTERS 4 12 2937 2944 scie scopus 000503114500022 2-s2.0-85075616710 Chemistry, Physical Electrochemistry Energy & Fuels Nanoscience & Nanotechnology Materials Science, Multidisciplinary Chemistry Electrochemistry Energy & Fuels Science & Technology - Other Topics Materials Science Article HYDROGEN EVOLUTION CHALCOPYRITE FILMS CDS REDUCTION CELLS LAYER