Silicon/Organic Heterojunction for Photoelectrochemical Energy Conversion Photoanode with a Record Photovoltage.
Silicon (Si) is a good photon absorption material for photoelectrochemical (PEC) conversion. Recently, the relatively low photovoltage of Si-based PEC anode is one of the most significant factors limiting its performance. To achieve a high photovoltage in PEC electrode, both a large barrier height and high-quality surface passivation of Si are indispensable. However, it is still challenging to induce a large band bending and passivate Si surface simultaneously in Si-based PEC photoanodes so far, which hinders their performance. Here, we develop a simple Si/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) heterojunction with large band banding and excellent surface passiviation for efficient PEC conversion. A chemically modified PEDOT:PSS film acts as both a surface passiviation layer and an effective catalyst simultaneously without sacrificing band bending level. A record photovoltage for Si-based PEC photoanodes as high as 657 mV is achieved via optimizing the PEDOT:PSS film fabrication process. The density of electron state (DOS) measurement is utilized to probe the passivation quality of the organic/inorganic heterojunction, and a low DOS is found in the Si/PEDOT:PSS heterojunction, which is in accordance with the photovoltage results. The low-temperature solution-processed Si/organic heterojunction photoanode provides a high photovoltage, exhibiting the potential to be the next-generation economical photoanode in PEC applications.
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
Wei
W
Cui
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
Shan
S
Wu
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
Fengjiao
F
Chen
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
Zhouhui
Z
Xia
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
Yanguang
Y
Li
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
Xiao-Hong
XH
Zhang
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
Tao
T
Song
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
Shuit-Tong
ST
Lee
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , 199 Ren'ai Road, Suzhou, Jiangsu 215123, China.
Baoquan
B
Sun
photoelectrochemical; silicon/organic heterojunction; surface passiviation