Title :
Multi-stacked InAs/GaNAs quantum dots with direct Si doping for use in intermediate band solar cell
Author :
Morioka, Takayuki ; Oshima, Ryuji ; Takata, Ayami ; Shoji, Yasushi ; Inoue, Takeru ; Kita, Takashi ; Okada, Yoshitaka
Author_Institution :
Grad. Sch. of Eng., Univ. of Tokyo, Tokyo, Japan
Abstract :
We investigated the effect of direct doping of quantum dots (QDs) with Si on the performance of QD solar cells (QDSCs). In order to control the Fermi level of intermediate band (IB) region, 25 layers of stacked InAs/GaNAs QDs were directly doped with Si impurity during the self-assembling stage of growth. A QDSC with Si doping shows an improved quantum efficiency (QE) in shorter wavelength region, which is from p-GaAs emitter layer. Further, the fact that applied external bias does not affect QE spectrum as well as photocurrent in QDSC with Si direct doping suggests that carrier collection has been enhanced in QD region as a result of reduction of recombination.
Keywords :
III-V semiconductors; elemental semiconductors; gallium compounds; indium compounds; semiconductor doping; semiconductor quantum dots; silicon; solar cells; Fermi level; InAs-GaNAs; QD solar cells; QE spectrum; Si; applied external bias; carrier collection; direct Si doping; intermediate band region; intermediate band solar cell; multistacked quantum dots; photocurrent; quantum efficiency; self-assembling stage;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2010 35th IEEE
Conference_Location :
Honolulu, HI
Print_ISBN :
978-1-4244-5890-5
DOI :
10.1109/PVSC.2010.5615944