Title:	Ultrafast Carrier Dynamics in InGaP/InGaAs/Ge Multi-Junction Solar Cells
Author(s):	V. Paraskeva, M. Hadjipanayi, S. Theocharides, A. Othonos, G.E. Georghiou
Keywords:	Multijunction Solar Cell, III-V Semiconductors, Ultrafast Spectroscopy
Topic:	Perovskites, other Non-Silicon-Based Photovoltaics and Multi-Junction Devices
Subtopic:	III-V and Related Compound Semiconductor Based Devices
Event:	36th European Photovoltaic Solar Energy Conference and Exhibition
Session:	3BV.1.56
Pages:	696 - 698
ISBN:	3-936338-60-4
Paper DOI:	10.4229/EUPVSEC20192019-3BV.1.56
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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Carrier dynamics with femtosecond resolution are investigated in the spectral region of InGaP/InGaAs in InGaP/InGaAs/Ge multi-junction solar cells indicating picosecond scale coupling effects between both junctions. Picosecond scale coupling between top and middle junction is evident by the presence of two peaks in the timeresolved differential reflection with 3.1 eV excitation and 1.38 eV probing energy at low temperatures (77 K). Measurements are repeated at higher temperatures (300 K) but no evidence of picosecond scale coupling effects in the material is found in this case. Moreover, measurements with 1.55 eV excitation are carried out aiming at the excitation of carriers far below the band-gap edge of the top junction and thus without the presence of coupling in the tandem.