Title :
Silicon nanowire arrays passivated by Al2O3/TiO2 stack layers
Author :
Yamada, Y. ; Kurokawa, Yusuke ; Kato, Shigeo ; Yamada, Akimasa
Author_Institution :
Dept. of Phys. Electron., Tokyo Inst. of Technol., Tokyo, Japan
Abstract :
To reduce reflectance on heterojunction silicon nanowire (SiNW) solar cells with the structure of ITO/p-type hydrogenated amorphous silicon(a-Si:H)/n-type SiNWs embedded in dielectric materials for passivation/n-type a-Si:H/back electrode, stack layers of aluminum oxide (Al2O3) and titanium oxide (TiO2) were deposited on SiNW arrays by atomic layer deposition (ALD). Refractive index of TiO2 prepared by ALD was 2.5 in a visible spectral range. The effective minority carrier lifetime in SiNW arrays embedded in an Al2O3/TiO2 stack layer of 94 μsec was obtained, which was comparable to an Al2O3 single layer. The surface reflectance of SiNW solar cells was drastically decreased below around 5% in all the wavelength range using the Al2O3/TiO2/Al2O3 stack layer.
Keywords :
alumina; amorphous semiconductors; atomic layer deposition; carrier lifetime; dielectric materials; elemental semiconductors; hydrogen; minority carriers; nanowires; passivation; refractive index; semiconductor heterojunctions; silicon; solar cells; titanium compounds; ALD; Al2O3-TiO2; ITO; ITO-p-type hydrogenated amorphous silicon; Si:H; atomic layer deposition; dielectric materials; effective minority carrier lifetime; heterojunction silicon nanowire solar cells with; n-type SiNWs; passivation-n-type a-Si:H-back electrode; reflectance reduction; refractive index; silicon nanowire arrays; stack layers; surface reflectance; time 94 mus; visible spectral range; Fabrication; Heterojunctions; Periodic structures; Photovoltaic cells; Reflectivity; Silicon; Surface treatment; atomic layer deposition; passivation; silicon nanowire; third generation photovoltaics;
Conference_Titel :
Photovoltaic Specialist Conference (PVSC), 2014 IEEE 40th
Conference_Location :
Denver, CO
DOI :
10.1109/PVSC.2014.6925539
