Atom-to-Device Simulation of MoO3/Si Heterojunction Solar Cell

Abstract

Metal oxides are commonly used in optoelectronic devices due to their transparency and excellent electrical conductivity. Based on its physical properties, each metal oxide serves as the foundation for a unique device. In this study, we opt to determine and assess the physical properties of MoO3 metal oxide. Accordingly, the optical and electronic parameters of MoO3 are evaluated using DFT (Density Functional Theory), and PBE and HSE06 functionals were mainly used in the calculation. It was found that the band structure of MoO3 calculated using PBE and HSE06 exhibited indirect semiconductor properties with the same line quality. Its band gap was 3.027 eV in HSE06 and 2.12 eV in PBE. Electrons and holes had effective masses and mobilities of 0.06673, −0.10084, 3811.11 cm2V−1s−1 and 1630.39 cm2V−1s−1, respectively. In addition, the simulation determined the dependence of the real and imaginary components of the complex refractive index and permittivity of MoO3 on the wavelength of light, and a value of 58 corresponds to the relative permittivity. MoO3 has a refractive index of between 1.5 and 3 in the visible spectrum, which can therefore be used as an anti-reflection layer for solar cells made from silicon. In addition, based on the semiconducting properties of MoO3, it was estimated that it could serve as an emitter layer for a solar cell containing silicon. In this work, we calculated the photoelectric parameters of the MoO3/Si heterojunction solar cell using Sentaurus TCAD (Technology Computing Aided Design). According to the obtained results, the efficiency of the MoO3/Si solar cell with a MoO3 layer thickness of 100 nm and a Si layer thickness of 9 nm is 8.8%, which is 1.24% greater than the efficiency of a homojunction silicon-based solar cell of the same size. The greatest short-circuit current for a MoO3/Si heterojunction solar cell was observed at a MoO3 layer thickness of 60 nm, which was determined by studying the dependency of the heterojunction short-circuit current on the thickness of the MoO3 layer.

First-Principles Calculation of MoO2 and MoO3 Electronic and Optical Properties Compared with Experimental Data

“…In Figure 3 With the aim of testing the effective reliability of the SCAN functional, the MoO structure was calculated again using the GGA PBEsol and the hybrid HSE06 funct (Figure 4). The results were compared with the those obtained with the MGGA app The indirect bandgap detected with PBEsol was 2.61 eV, which means that the Ge MoO 3 is an indirect bandgap material; thus, the energy band gap resulted in 3.16 eV (with a direct band gap of 2.27 eV) (Figure 3C), and, to the best of our knowledge, this value is the one that best matches the experimental one of 3.2 eV [12], also considering other theoretical studies [2], where a band gap of 3.027 eV was found with the HSE06 method [38]. Similarly to the MoO 2 , even for MoO 3 the PDOS calculation showed that the valence band derived from the oxygen 2 p states with a small contribution of the d state of Mo.…”

“…The indirect bandgap detected with PBEsol was 2.61 eV, which means that the Generalized Gradient Approximation tended to underestimate the energy gap between valence and conduction bands. Using HSE06, the incorporation of a portion of the exact exchange from Hartree-Fock theory allowed us to obtain an indirect bandgap value of 3.03 eV, which is also in line with other previously conducted studies [38]. In any case, the SCAN functional was found to be the most accurate for the prediction of electrical properties of Mo-O-based systems, and for this reason, all the next calculations reported were performed using this MGGA approach.…”

“…Scanlon et al [2] used the generalized gradient approximation (GGA) with PBE in the plane wave basis set to study both MoO 3 and MoO 2 . More recently, Gulomov et al [38] used and compared two DFT approaches, namely, PBE and HSE06 functionals, calculating in both cases the band gap energy of MoO 3 that was found to be, in the best case from HSE06 calculation, 3.027 eV.…”

Investigation of n-ZnO/p-Si and n-TiO2/p-Si Heterojunction Solar Cells: TCAD + DFT

“…Nevertheless, it is known that different metal oxides may require different functionalities, not only PBESol. In our previous scientific work [65], it was found that the quality of curves of band structure of MoO3 calculated using the HSE06 (Heyd-Scuseria-Ernzerhof) hybrid functional and the PBE functional is identical. Therefore, quality of curves of band structure calculated HSE06, GGA functionals and experiment may be the same.…”

Optoelectrical Properties of Hexamine Doped-Methylammonium Lead Iodide Perovskite under Different Grain-Shape Crystallinity

“…Perovskite solar cells (PSC) have become the focus of investigation around the world due to their high performance in converting light into electrical energy, rivaling that of monocrystalline solar cells [ 1 , 2 , 3 ], and far overcoming other types of solar cells, including organic solar cells and hetero-junction solar cells [ 4 , 5 ]. The optoelectrical properties of the perovskite material, which are easy to change through compositional engineering [ 6 , 7 ], have increased the opportunity to continuously improve the performance of light to electrical energy conversion [ 8 , 9 ].…”