Open AccessFrequency response of the external quantum efficiency in multijunction solar cells
Author(s) -
Nicolás Márquez Peraca,
D. Taner Bilir,
Behrang H. Hamadani
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.00a709
Subject(s) - photocurrent , quantum efficiency , optoelectronics , optics , amplifier , physics , bandwidth (computing) , phase modulation , context (archaeology) , amplitude , materials science , phase noise , telecommunications , computer science , paleontology , cmos , biology
The frequency dependence of the external quantum efficiency (EQE) of high-quality multijunction solar cells was examined by the modulated photocurrent spectroscopy method via an optical setup comprised of a light-pipe-coupled compact LED array. The optical excitation was achieved through sinusoidal electrical modulation of an appropriate LED by a custom-designed, high bandwidth amplifier. We observed unique features in the amplitude and phase data of the EQE frequency sweeps that are very sensitive to various subcell parameters and light bias conditions. These features are discussed extensively within the context of an AC equivalent circuit model, showing remarkable agreement between the experimental data and the proposed model.