Structural, morphological, and optical characterizations of Mo, CrN and Mo:CrN sputtered coatings for potential solar selective applications

Abstract

Mo, CrN, and Mo:CrN sputtered coatings synthesized onto silicon Si(100) substrates were investigated as solar selective surfaces and their potential applications in optical devices. These coatings were characterized using XRD, SEM, UV-Vis, and FTIR techniques. XRD investigation, showed a change in CrN thin film crystallite characteristic due to Mo doping. Compared to the CrN coating, the Mo:CrN film has a higher lattice parameter and lower grain size of 4.19 nm and 106.18 nm, respectively. FESEM morphology confirmed the decrement in Mo:CrN crystal size due to Mo doping. Optical analysis showed that in the visible range of the solar spectrum, the CrN coatings exhibit the highest solar absorptance of 66% while the lowest thermal emittance value of 5.67 was recorded for the CrN coating doped with Mo. Consequently, the highest solar selectivity of 9.6, and the energy band-gap of 2.88 eV were achieved with the Mo-doped CrN coatings. Various optical coefficients such as optical absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constants, and energy loss functions of these coatings were also estimated from the optical reflectance data recorded in the wavelength range of 190-2300 nm.

A first-principles study of the electronic, structural, and optical properties of CrN and Mo:CrN clusters

“…The HOMO/LUMO gap (∆E) as calculated from the DOS spectra (see Figure4) are presented in Table3. This result is in good agreement with that of experimental studies[63].the DOS spectra analysis of the Cr 3 Mo 2 N 3 and Cr 4 MoN 3 clusters indicate their magnetic susceptibility as their MOs are split into alpha and beta MOs, which may also be used in spintronic devices[65].…”

Annealing effects on microstructural, optical, and mechanical properties of sputtered CrN thin film coatings: Experimental studies and finite element modeling

“…absorptance, β of these coatings was calculated using the Beckman-Duffie method [40,41]. The UV-Vis reflectance data were used to calculate the optical constants such as solar absorptance, band-gap, refractive index, dielectric constants and energy loss functions for as-deposited and post annealed of CrN coatings.…”

Studies of annealing impact on the morphological, opto-dielectric and mechanical behaviors of molybdenum-doped CrN coatings

“…As the annealing temperature increases, the overall crystalline size decreases slightly, but the grain size initially decreases from room temperature to 500 C, and then increases from 500 to and 800 °C, respectively. The CrN data from our previous work [27] is also included for comparison purpose.…”

“…The CrN, and Mo-doped CrN sputtered thin film coatings were investigated to comprehend their structural, spectral selective, and mechanical features in both as deposited and annealed at various temperatures [27,28]. Various optical coefficients such as optical absorption coefficient, optical band-gaps, complex refractive index, dielectric constants, and energy loss functions of these coatings were thoroughly inspected.…”