Optical absorption and photoluminescence of narrow‐Gap Hg_1−x−yCd_xMn_ySe single crystals

Abstract

The optical properties of Hgl-,-,Cd,Mn,Se (z = 0.09 to 0,ll. y = 0.02 to 0.03) single crystals are investigated by means of infrared transmission and photoluminescence. The photoluminescence is promoted by manganese doping. The presence of Mn significantly improves the structure of mercury selenides. The optical dielectric constant, refractive index, and energy gap are determined as functions of temperature.Die optischen Eigenschaften von Hgl -,-,Cd,Mn,,Se (z = 0,09 bis 0 , l l ; y = 0,02 bis 0,03) wurden rnittels Infrarottransmission und Photolumineszenz untersucht. Das Auftreten von Photolumineszenz wird durch die Mangandotierung des Materials begunstigt. Das Vorhandensein von Mn verbessert die strukturellen Eigenschaften der Quecksilberselenide. Die optische Dielektrizitatskonstante, der Brechungsindex und die Bandliicke wurden in Abhangigkeit von der Temperatur bestimmt .

Quaternary semimagnetic Hg 1-x-yCdxMnySe crystals for optoelectronic application

“…The well resolved spin structure of the longitudinal and transverse magnetoresistances without of a visible shift between their SdH peaks proves, at least, a low T D originated due to collisions. This finding is in line with the statement about improved crystalline structure of spin doped semiconductors, derived earlier from our optical measurements in quaternary semimagnetics [8,9,31]…”

“…According to equation 2 this indicates either no contribution of the exchange interaction in sample 2 or a very small negative contri-bution to g* if the latter exists. One could even suspect whether the manganese ions present in this sample, but our earlier studies by means of far-infrared phonon spectroscopy ( reflection, transmission [9]) , as well as the data of microprobe analysis surely verify the manganese presence of a proper concentration. Whence we conclude that the exchange contribution in the range of small E g of semimagnetics becomes also strongly dependent on electron concentration being nearly suppressed at n ≈ 1⋅10 17 cm -3 .…”

“…It was determined from the earlier optical measurements (see Ref. [9]) that in the Hg 1-x-y Cd x Mn y Se crystals of similar composition dE dT g / equals to 0.54 meV/K. When this temperatureinduced «opening» the energy gap is taken into account its contribution to the total B 0 − peak shift gains approximately 12% of that observed experimentally only.…”

“…They coincide within 2% accuracy with those found from Hall measurements. The E g value was determined from the optical studies in narrow-gap Hg 1-x-y Cd x Mn y Se [9]. Parameters m n and m e are the electron mass at bottom of conduction band and the mass of free electron, respectively.…”

“…Following these find-ings we take the composition x = 0.1 and y = 0.02, because at zero magnetic field B the energy gap in Hg 1-x-y Cd x Mn y Se is opened in the same manner as in Hg 1-x' Cd x' Se with effective concentration x' = x + 2.52y (see Ref. [9]). With such adjusted composition we believe to meet the most favorable conditions for observation of exchange interaction effect on the SdH spin-related structure in Hg 1-x-y Cd x Mn y Se.…”