Title :
Ultrahigh-resolution direct observation of mini-bands formed in InGaAs/AlGaAs superlattice
Author :
Shimura, Daisuke ; Ichihashi, Fumiaki ; Nishitani, Kenji ; Harada, Shingo ; Kuwahara, Masashi ; Ito, Takao ; Matsunami, M. ; Kimura, Shin-ichi ; Sakai, Tadashi ; Tagawa, Masaki ; Ujihara, Toru
Author_Institution :
Dept. of Mater. Sci. & Eng., Nagoya Univ., Nagoya, Japan
Abstract :
Mini-bands formed in superlattice structures are often used for an intermediate-band solar cell. In order to design an optimized structure, it is important to measure the mini-band dispersions which influence transport properties and solar-energy conversion efficiency. In this study, we directly observed the dispersions of mini-bands formed in InGaAs/AlGaAs quantum-well superlattices by angle-resolved photoemission spectroscopy with synchrotron radiation light. The short-period energy dispersions due to the mini-bands around the X-valley were clearly obtained. In addition, the effective mass coefficient of each mini-band could be individually evaluated.
Keywords :
III-V semiconductors; aluminium compounds; gallium arsenide; indium compounds; photoelectron spectra; semiconductor quantum wells; semiconductor superlattices; solar cells; synchrotron radiation; InGaAs-AlGaAs; X-valley; angle-resolved photoemission spectroscopy; energy dispersion; intermediate-band solar cell; mass coefficient; mini-band dispersion; quantum-well superlattice structure; solar-energy conversion efficiency; synchrotron radiation light; ultrahigh-resolution direct observation; Indium gallium arsenide; Photoelectricity; Photonics; Photovoltaic cells; Quantum wells; Spectroscopy; Superlattices; intermediate-band solar cell; mini-band; photoemission spectroscopy; quantum-well (QW) superlattice;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2013 IEEE 39th
Conference_Location :
Tampa, FL
DOI :
10.1109/PVSC.2013.6744154
