XXVII International Symposium "Nanophysics and Nanoelectronics", Nizhny Novgorod, 13 - 16 March 2023

Photomodulation optical spectroscopy of CdHgTe graded band gap heterostructures

O. S. Komkov^a, M. V. Yakushev<sup>b

a</sup> Saint Petersburg Electrotechnical University "LETI", 197022 St. Petersburg, Russia
^b Rzhanov Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia

Abstract: Multilayer mercury–cadmium–telluride photodetecting heterostructures grown by molecular beam epitaxy on Si and GaAs substrates were studied using the infrared photoreflectance method. Based on the period of Franz–Keldysh oscillations observed in the photoreflectance spectra, the strength of the built-in electric field near the “working layer – graded band gap near-surface layer” heterointerface was determined in a contactless way. An analytical calculation of distribution of such field over the structure depth has specified the region in which the photomodulation signal is formed. The experimentally obtained field values turned out to be higher than the calculated ones, which is explained by the influence of the photovoltaic effect.

Keywords: photoreflectance, mercury–cadmium–telluride, MCT, CdHgTe, built-in electric field, Fourier transform infrared spectroscopy, Franz–Keldysh oscillations.

Received: 24.08.2023
Revised: 01.09.2023
Accepted: 01.09.2023

DOI: 10.61011/FTP.2023.06.56469.33k

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