Optical properties of CuAlSe2

Abstract

We have determined the complex dielectric tensor components of the chalcopyrite semiconductor CuAlSe2 in the energy range between 1.4 and 5.2 eV, at room temperature, using spectroscopic ellipsometry. We present results obtained on two single crystals grown by the traveling-heater method using In solvent. Values of refractive indices n, extinction coefficients k and normal-incidence reflectivity R in the two independent polarizations are reported. The structures observed in the energy region studied are analyzed by fitting the second-derivative spectra d2ε(ω)/dω2 to analytic critical-point line shapes. The obtained energies are assigned to certain electronic interband transitions by comparison with existing band structure calculations.

Optical properties of CuAlS2 with small indium content

“…The Table 1). [3,5], and with due regard to the energy of each band obtained by theoretical band structure calculations for CuAlS 2 and CuInS 2 [11]. The results of our assignment are listed in the fourth column of Table 1.…”

“…The optical parameters such as refractive indices and dielectric constants, which provide information on inter-band optical transitions, are of key importance for various optical applications of this material. Until now the optical constants of many Cu-III-VI 2 ternary compounds (CuInSe 2 [3,4], CuInS 2 [3], CuGaSe 2 [3,4], CuGaS 2 [3], CuAlSe 2 [5] and CuGa x In 1-x Se 2 [6]) have been studied by spectroscopic ellipsometry (SE). However, CuAlS 2 is not among the above compounds and its optical constants above the energy gap have yet to be studied.…”

Thin‐Film Semiconductors Deposited in Nanometric Scales by Electrochemical and Wet Chemical Methods for Photovoltaic Solar Cell Applications

“…The chemicals used as the cationic and the anionic precursors in such a method are, respectively: (i) copper(II) sulfate pentahydrate (CuSO 4 · 5H 2 O) solution complexed with a mixture of 2 N TEA and 2 N hydrazine hydrate ( HH ), the Figure 5. 20 The scheme of a modifi ed chemical method for the deposition of Cu 2 S fi lms onto glass substrates: A, cationic precursor (copper(II) sulfate pentahydrate); B, ion -exchange water; C, anionic precursor (sodium sulfi de); D, ion -exchange water [202] . It is well established that copper selenide usually exists as the copper(I) form (CuSe or Cu 3 Se 2 ) [202 -205] .…”

“…Polycrystalline thin fi lms can be prepared by chemical vapor deposition ( CVD ), as well as vacuum evaporation [3,4] , sputtering [5] , molecular beam epitaxy [6] , layer -wise chemisorptions [7] , chemical vapor deposition [8,9] and liquid -phase atomic layer expitaxy [10] , physical vapor deposition ( PVD ) [11] , spray pyrolysis [12] , molecular beam epitaxy [13 -15] , low -pressure metal organic vapor -phase epitaxy ( LPMOVE ) [16,17] , successive ionic layer adsorption and reaction ( SILAR ) [18] , pulsed layer deposition ( PLD ) [19] , traveling heater ( TH ) [20] , radiofrequency diode sputtering ( RDS ) [21] , chemical wet deposition, and electrodeposition [22 -25] . Each thin -fi lm deposition technique has its own advantages and disadvantages.…”

Dispersion of the linear and nonlinear optical susceptibilities of the CuAl(S1−xSex)2 mixed chaclcopyrite compounds

“…41,42 The birefringence is the difference between the extraordinary and ordinary refraction indices, DnðxÞ ¼ n e ðxÞ À n o ðxÞ, where n o ðxÞ is the index of refraction for an electric field oriented along the c-axis and n e ðxÞ is the index of refraction for an electric field perpendicular to the c-axis. It is clear that the birefringence is crucial only in the non-absorbing spectral range, which is below the energy gap.…”