Presentation Information
[9a-E217-7]Luminescence characterization and energy-level alignment of Er3+ in GaAs for photon-ratchet intermediate-band solar cells
〇Yuka Kitano1, Kota Toda1, Taiki Kontani1, Shigeo Asahi1, Yukihiro Harada1, Yusuke Oteki2, Myeongok Kim2, Yuya Makino3, Tatsuki Kawamura3, Tomah Sogabe4, Yoshitaka Okada2, Takashi Kita1 (1.Grad. Sch. of Eng., Kobe Univ., 2.RCAST, The Univ. of Tokyo, 3.Grad. Sch. of Informatics and Eng., The Univ. of Electro-Communications, 4.i-PERC, The Univ. of Electro-Communications)
Keywords:
Gallium arsenide,Erbium,Intermediate-band solar cell
We investigated a ratchet-type intermediate-band solar cell consisting of Er-doped GaAs and InAs quantum dots to improve the utilization of sub-bandgap photons. Photoluminescence measurements were performed to evaluate the temperature and excitation-power dependence of the quantum-dot emission and to identify Er-related luminescence. The quantum-dot emission showed clear temperature dependence and increased almost linearly with excitation power. A weak emission attributed to an Er transition was also observed. Future work will focus on selectively exciting the quantum dots and detecting Er emission to clarify the energy-transfer process between the quantum dots and Er ions.