Title :
Long carrier lifetime in ultrahigh-density InAs quantum-dot sheet of intermediate band solar cells
Author :
Shiokawa, Miyuki ; Saputra, Edes ; Sakamoto, Kazumitsu ; Yamaguchi, Kazuhiro
Author_Institution :
Dept. of Eng. Sci., Univ. of Electro-Commun., Chofu, Japan
Abstract :
In-plane ultrahigh-density InAs quantum dots with 3 - 5 × 1011 cm-2 were grown on the GaAsSb/GaAs(001) by MBE. PL properties of the ultrahigh density QDs with small size revealed lateral coupling of electrons in the in-plane QD sheet. Long PL decay time of 4-6 ns was observed for laterally coupled QD sheet, spite of type-1 band alignment. The PL decay time drastically decreased under high electric field. It was explained by change of the electronic states and electron escape. For forward bias voltage, long PL decay time of 10 ns was observed.
Keywords :
arsenic compounds; electric fields; gallium arsenide; indium compounds; semiconductor quantum dots; solar cells; GaAsSb-GaAs; InAs; PL decay time; QD sheet; electric field; electron escape; electronic states; intermediate band solar cells; lateral electron coupling; quantum dots; time 10 ns; time 4 ns to 6 ns; type-1 band alignment; ultrahigh density QD; ultrahigh-density quantum-dot sheet; Charge carrier lifetime; Couplings; Electric fields; Gallium arsenide; Molecular beam epitaxial growth; Photovoltaic cells; Quantum dots; GaAsSb; InAs; PL decay time; intermediate band solar cells; quantum dots;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2013 IEEE 39th
Conference_Location :
Tampa, FL
DOI :
10.1109/PVSC.2013.6744155
