TY - GEN
T1 - Quantitative analysis of InAs quantum dot solar cells by photoluminescence spectroscopy
AU - Tamaki, Ryo
AU - Shoji, Yasushi
AU - Lombez, Laurent
AU - Guillemoles, Jean François
AU - Okada, Yoshitaka
N1 - Publisher Copyright:
© 2018 SPIE.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - We have quantitatively investigated the two-step photon absorption in quantum dot solar cells (QDSCs) by using absolute intensity calibrated photoluminescence (PL) spectroscopy. Multi-stacked InAs/AlGaAs QDs were fabricated in the i-region of p-i-n single-junction solar cells by molecular beam epitaxy. Hyperspectral imaging, which combines both the spatial and spectral dimensions of the luminescence, was used to investigate QD ground state PL at room temperature. Two lasers simultaneously excited the QDSCs to characterize two-step photon absorption. An excitation laser caused interband transition to generate photo-carriers in QDs, and the other infrared (IR) laser excited intraband transition from the QD states. As the result of two-step photon absorption, reduction in PL intensity was clearly observed under IR bias excitation. We compared absolute PL intensity with and without IR illumination, and obtain quasi-Fermi level splitting and two-step photon absorption efficiency in QDSCs under study. Compared with the photocurrent measurements, PL spectroscopy performed under open-circuit conditions, so that higher carrier filling ratio can be realized in QDs. Furthermore, PL can characterize fundamental transition on two-step photon absorption because photocurrent production needs carrier extraction to the external circuit. Quantitative analysis of two-step photon absorption by PL spectroscopy could clarify physical insights, and it would be beneficial to realize high efficiency intermediate band solar cells.
AB - We have quantitatively investigated the two-step photon absorption in quantum dot solar cells (QDSCs) by using absolute intensity calibrated photoluminescence (PL) spectroscopy. Multi-stacked InAs/AlGaAs QDs were fabricated in the i-region of p-i-n single-junction solar cells by molecular beam epitaxy. Hyperspectral imaging, which combines both the spatial and spectral dimensions of the luminescence, was used to investigate QD ground state PL at room temperature. Two lasers simultaneously excited the QDSCs to characterize two-step photon absorption. An excitation laser caused interband transition to generate photo-carriers in QDs, and the other infrared (IR) laser excited intraband transition from the QD states. As the result of two-step photon absorption, reduction in PL intensity was clearly observed under IR bias excitation. We compared absolute PL intensity with and without IR illumination, and obtain quasi-Fermi level splitting and two-step photon absorption efficiency in QDSCs under study. Compared with the photocurrent measurements, PL spectroscopy performed under open-circuit conditions, so that higher carrier filling ratio can be realized in QDs. Furthermore, PL can characterize fundamental transition on two-step photon absorption because photocurrent production needs carrier extraction to the external circuit. Quantitative analysis of two-step photon absorption by PL spectroscopy could clarify physical insights, and it would be beneficial to realize high efficiency intermediate band solar cells.
KW - III-V semiconductor
KW - InAs quantum dot
KW - intermediate band solar cell
KW - intersubband transition
KW - photoluminescence spectroscopy
KW - quantum dot solar cell
U2 - 10.1117/12.2291465
DO - 10.1117/12.2291465
M3 - Conference contribution
AN - SCOPUS:85048425171
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Physics, Simulation, and Photonic Engineering of Photovoltaic Devices VII
A2 - Freundlich, Alexandre
A2 - Sugiyama, Masakazu
A2 - Lombez, Laurent
PB - SPIE
T2 - Physics, Simulation, and Photonic Engineering of Photovoltaic Devices VII 2018
Y2 - 31 January 2018 through 1 February 2018
ER -