Preparation and optical characterization of Cu2ZnGeSe4 thin films

Abstract

Esta es la versión de autor del artículo publicado en: This is an author produced version of a paper published in: substrates at a substrate temperature of 300 and 420 K. CZGSe films were characterized by Xray diffraction (XRD), energy dispersive X-ray spectroscopy, scanning electron microscopy and by the method of normal incidence transmittance and reflectance. XRD studies reveal an improved crystallinity of the polycrystalline CZGSe films with tetragonal structure when the substrate temperature was increased. The refraction index and extinction coefficient were extracted from the optical measurements. Spectral dependence of absorption coefficient and the energy band gaps values of CZGSe films were also determined.

Combinatorial and machine learning approaches for the analysis of Cu2ZnGeSe4: influence of the off-stoichiometry on defect formation and solar cell performance

“…5,[7][8][9] In addition, the partial substitution of Sn by Ge increases the bandgap of the kesterite semiconductor material enabling the creation of a graded bandgap through the development of indepth compositional engineering strategies. 10,11 On the other hand, the total substitution of Sn by Ge (CZGSSe) appears as an even more promising approach since, in addition to completely avoiding Sn-related issues, the wider bandgap of the material ($1.5 eV for CZGSe and $2.2 eV for CZGS) 12,13 opens the door to semi-transparent, tandem and photocatalytic water splitting applications. Signicant advances have been made in the last years in pure Ge kesterite solar cells leading to CZGSe devices with efficiencies of up to 8.5%.…”

Hopping magnetotransport of the band-gap tuning Cu2Zn(SnxGe1−x)Se4crystals

“…Some preparation details of crystal and thin films, as well as structural studies were published in [11][12][13][14]. The optical properties were studied by means of transmittance [13,[15][16][17][18], reflectance [13,[15][16][17][18][19], photoluminescence [10,15,20,21] and ellypsometry [22][23][24] measurements. The room temperature electrical properties [13,17], as well as the temperature dependence of resistivity in CZGeSe single crystals [25] were investigated so far.…”

A Comprehensive Review on the Recent Strategy of Cation Substitution in CZTS(Se) Thin Films to Achieve Highly Efficient Kesterite Solar Cells

“…This synthesized CZGeSe absorber exhibits an optical bandgap of 1.5 eV, which is very near to optimal bandgap of solar energy harvesting devices. Levcenko et al observed that the optical bandgap of ion beam‐sputtered CZGeSe thin film decreased from 1.52 to 1.17 eV as the substrate temperature increased from 300 to 420 K. [ 90 ] The possible existence of the secondary phases like Cu 2 GeSe 3 and Cu 1.8 Se with E g of 0.77 [ 91 ] and 1.23 eV, [ 92 ] respectively, might be responsible for the reduction of the derived bandgap values for CZGeSe. Disordered structure of CZGSe film same as Sn‐based kesterites (Cu 2 ZnSnS 4 ) may also be responsible for this deviation of bandgap values from the derived range of values of 1.29–1.63 eV for a single‐crystal CZGeSe thin film.…”