TY - JOUR
T1 - Photoelectrochemical performances of the cubic AgSnSe2 thin film electrodes created using the selenization of thermal evaporated Ag-Sn metal precursors
AU - Cheng, Kong Wei
AU - Chou, Yi
N1 - Publisher Copyright:
© 2017 Taiwan Institute of Chemical Engineers
PY - 2018/4
Y1 - 2018/4
N2 - In this study, we prepared the cubic AgSnSe2 thin film photoelectrodes on substrates using the selenization of Ag–Sn metal precursors and examined the influence of silver content in samples on their photoelectrochemical properties in the aqueous solution. With the selenization temperature kept at 410 °C for 1 h in the selenization apparatus, the cubic AgSnSe2 samples can be obtained. The results of phase characterization show that the phase change from the cubic AgSnSe2 to the cubic Ag8SnSe6 phase takes place at the selenization temperature between 425 to 440 °C. The optical energy band gaps, carrier concentrations, and mobilities of samples are in the range of 1.24–1.30 eV, 1.75 × 1018–4.68 × 1019 cm−3, and 43–253 cm2/V/s, respectively. It was found that the sample with the [Ag]/[Ag + Sn] molar ratio of 0.48 had a maximum photo-enhancement current density of 1.26 mA/cm2 at an external bias of + 1.23 V vs. the reverse hydrogen electrode in the 0.35 M Na2S + 0.25 M K2SO3 aqueous solution. The electrochemical impedance spectra of samples in the aqueous solution containing S2− and SO3 2− ions were also employed to examine the possible reaction mechanisms taking place at the sample surfaces.
AB - In this study, we prepared the cubic AgSnSe2 thin film photoelectrodes on substrates using the selenization of Ag–Sn metal precursors and examined the influence of silver content in samples on their photoelectrochemical properties in the aqueous solution. With the selenization temperature kept at 410 °C for 1 h in the selenization apparatus, the cubic AgSnSe2 samples can be obtained. The results of phase characterization show that the phase change from the cubic AgSnSe2 to the cubic Ag8SnSe6 phase takes place at the selenization temperature between 425 to 440 °C. The optical energy band gaps, carrier concentrations, and mobilities of samples are in the range of 1.24–1.30 eV, 1.75 × 1018–4.68 × 1019 cm−3, and 43–253 cm2/V/s, respectively. It was found that the sample with the [Ag]/[Ag + Sn] molar ratio of 0.48 had a maximum photo-enhancement current density of 1.26 mA/cm2 at an external bias of + 1.23 V vs. the reverse hydrogen electrode in the 0.35 M Na2S + 0.25 M K2SO3 aqueous solution. The electrochemical impedance spectra of samples in the aqueous solution containing S2− and SO3 2− ions were also employed to examine the possible reaction mechanisms taking place at the sample surfaces.
KW - Photoelectrochemical cell
KW - Photoelectrode
KW - Ternary metal selenides
KW - Thermal evaporation
UR - http://www.scopus.com/inward/record.url?scp=85040346782&partnerID=8YFLogxK
U2 - 10.1016/j.jtice.2017.11.029
DO - 10.1016/j.jtice.2017.11.029
M3 - 文章
AN - SCOPUS:85040346782
SN - 1876-1070
VL - 85
SP - 56
EP - 65
JO - Journal of the Taiwan Institute of Chemical Engineers
JF - Journal of the Taiwan Institute of Chemical Engineers
ER -