Open AccessAnomalous photocurrent in wide InGaN quantum wells
Author(s) -
Artem Bercha,
Witold Trzeciakowski,
G. Muzioł,
M. Siekacz,
C. Skierbiszewski
Publication year - 2020
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.382646
Subject(s) - photocurrent , quantum well , optoelectronics , optics , materials science , physics , diode , light intensity , chopper , photon , laser , voltage , quantum mechanics
We show that in a wide In 0.17 Ga 0.83 N quantum well, placed within an undoped region of the pin diode, a photocurrent in the forward direction is observed. The photocurrent switches to reverse direction when the light intensity is increased and/or photon energy is above the bandgap of the quantum barrier. We propose a model showing that the anomalous photocurrent is due to the fact that when the carriers are pumped into the wide quantum well they cannot recombine until the built-in field is screened. For low-intensity light it takes a long time (milliseconds) for the screening to occur and during that time we observe current flowing in the forward direction. This current originates from the reorganization of carriers forming the depletion regions, rather than directly from the photogenerated carriers. The observed effects lead to the dependence of PC spectra on chopper frequency and on light power. They may also affect the operation of laser diodes and solar cells with wide InGaN quantum wells.