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Title: Microscopic observation of carrier-transport dynamics in quantum-structure solar cells using a time-of-flight technique

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4927612· OSTI ID:22486395
; ; ;  [1]; ; ; ;  [2]; ;  [3]
  1. School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032 (Japan)
  2. Graduate School of Engineering, Kobe University, Nada-ku, Kobe 657-8501 (Japan)
  3. Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 153-8904 (Japan)

In this study, we propose a carrier time-of-flight technique to evaluate the carrier transport time across a quantum structure in an active region of solar cells. By observing the time-resolved photoluminescence signal with a quantum-well probe inserted under the quantum structure at forward bias, the carrier transport time can be efficiently determined at room temperature. The averaged drift velocity shows linear dependence on the internal field, allowing us to estimate the quantum structure as a quasi-bulk material with low effective mobility containing the information of carrier dynamics. We show that this direct and real-time observation is more sensitive to carrier transport than other conventional techniques, providing better insights into microscopic carrier transport dynamics to overcome a device design difficulty.

OSTI ID:
22486395
Journal Information:
Applied Physics Letters, Vol. 107, Issue 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English