Pressure-Induced Bandgap Engineering and Tuning Optical Responses of Cd0.25Zn0.75S Alloy for Optoelectronic and Photovoltaic Applications

Abstract

The manipulation of composition and pressure, which affect the structure and, as a result, lead to new desired properties, is particularly significant for optimizing device performance. By considering the importance of pressure treatment, this study explores bandgap engineering and tuned optical responses of the ternary Cd0.25Zn0.75S alloy over a pressure range of 0–20 GPa using density functional theory. The functional material exhibits cubic symmetry at all pressures, and its bulk modulus increases with pressure. It is a direct bandgap semiconductor at Γ symmetry point, and its bandgap energy increases from 3.35 eV to 3.86 eV with an increase in pressure. Optical properties change with pressure, such that the absorption coefficient increases and absorbs near-ultraviolet light, while the static dielectric constant and static refractive index both increase with pressure. The effects of pressure on other optical parameters such as dielectric constant, extinction coefficient, refractive index, optical conductivity, and reflection are also explored. These findings provide significant theoretical guidance for the use of the Cd0.25Zn0.75S semiconductor in fabricating optoelectronic and photovoltaic devices functioning at varying pressure ranges and altitudes.

Theoretical Insights into Pressure‐Driven Stability and Optoelectronic Response of Cd0.75Zn0.25S Alloy for Blue–Violet Display

“…At atmospheric pressure, the Born stability conditions were tested to justify mechanical stability with criteria as C 11 − C 12 > 0, C 44 > 0, and C 11 + 2 C 12 > 0, and under the pressure impact, the modified stability conditions are also included: C 11 + C 12 + P > 0, C 11 − C 12 − 2 P > 0, and C 44 − P > 0. [ 32 ] All stability conditions are satisfied at a pressure range of 0–20 GPa (see Figure ), which shows that Cd 0.75 Zn 0.25 S is a mechanically stable alloy. Figure 1a–d presents ternary alloy's elastic coefficients and stability criteria at varying pressures.…”

Morphological, Photoluminescence, and Electrical Measurements of Rare-Earth Metal-Doped Cadmium Sulfide Thin Films

“…However, there are some challenges associated with the use of CdS as a buffer layer. CdS has a relatively wide bandgap of ∼2.4 eV, which can absorb blue light and decrease the overall device efficiency. − …”

“…CdS has a relatively wide bandgap of ∼2.4 eV, which can absorb blue light and decrease the overall device efficiency. 64 − 67 …”

Performance Analysis and Optimization of a PBDB-T:ITIC Based Organic Solar Cell Using Graphene Oxide as the Hole Transport Layer

“…The current improvement increased PCE by 18% in 2020 due to recent developments, owing mainly to the introduction of these unique nonfullerene acceptors (NFA) [ 18 , 19 ]. NFA acceptors are not associated with stability issues and play a key role in enhancing the performance of organic solar cells (OSC) [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. PEDOT:PSS is widely used as a hole transport material (HTM) in traditional OSC [ 29 , 30 ] because it provides better hole transportation and has high transmission.…”