Title :
Improved dark current characteristics of GaAs/InGaAs multi-quantum well solar cells fabricated by atomic H-assisted molecular beam epitaxy
Author :
Okada, Yoshitaka ; Seki, Satoshi ; Hagiwara, Yoshinobu ; Kawabe, Mitsuo
Author_Institution :
Inst. of Appl. Phys., Tsukuba Univ., Ibaraki, Japan
Abstract :
The authors have fabricated shallow and deep InGaAs/GaAs multi-quantum well (MQW) solar cell diodes by atomic H-assisted molecular beam epitaxy (H-MBE) and the conventional MBE. The measured dark currents in H-MBE diodes were found to be 1~2 orders of magnitude smaller than in MBE for both MQW and p-i-n diodes. This was due to the effect of defect passivation by H-atoms. The temperature dependence of dark currents were also characterized in order to determine the upper limit of potential depth for the photo-generated carriers to escape efficiently out of the quantum well and thereby minimize the recombination currents at the MQW heterointerfaces. It was concluded that for a given 10-period InGaAs/GaAs MQW diode, In composition should be set <~0.1
Keywords :
III-V semiconductors; electron-hole recombination; gallium arsenide; indium compounds; molecular beam epitaxial growth; p-n heterojunctions; quantum well devices; semiconductor device measurement; semiconductor device testing; semiconductor growth; semiconductor quantum wells; solar cells; GaAs-InGaAs; GaAs/InGaAs multi-quantum well solar cells; atomic H-assisted molecular beam epitaxy; dark currents; defect passivation; heterointerfaces; photo-generated carriers; potential depth; recombination currents; temperature dependence; Atomic beams; Atomic layer deposition; Atomic measurements; Dark current; Gallium arsenide; Indium gallium arsenide; Molecular beam epitaxial growth; P-i-n diodes; Photovoltaic cells; Quantum well devices;
Conference_Titel :
Photovoltaic Specialists Conference, 2000. Conference Record of the Twenty-Eighth IEEE
Conference_Location :
Anchorage, AK
Print_ISBN :
0-7803-5772-8
DOI :
10.1109/PVSC.2000.916123
