Improved Optical and Electronic Properties of Single-Layer MoS2 by Co Doping for Promising Intermediate - Band Materials

Owing to its unique optical and electronic characteristics, two-dimensional MoS2 has been widely explored in the past few years. Using first-principle calculations, we shed light on that the substitutional doping of Co can induce the half-filled intermediate states in the band gap of monolayer MoS2. The calculated absorption spectrum presents an enhancement of the low-energy photons (0.8 eV–1.5 eV), which is desired for intermediate-band solar cells. When the doping concentration increases, the reflectivity of the infrared and visible light (0.8 eV-4.0 eV) reduces, resulting in an improved photovoltaic efficiency of the material. Our results shed light on the application of heavily Co-doped MoS2 as intermediate band solar cell material.

Numerical Investigation into Photovoltaic Performance of Organolead Trihalide Perovskite Quantum Dot Intermediate Band Solar Cell

In this work, an intermediate band solar cell (IBSC) model consisting of MAPbI3 quantum dots (QD) and MAPbCl3 barrier material is explored analytically with MATLAB. Titanium di-oxide (TiO2) is used as transport layer for electron and Spiro-OMeTAD (2,2',7,7'-tet-rakis (N,N'-di-p-methoxyphenylamine)–9,9' spirobifluorene) is used as transport layer for hole. Fluorine-doped tin oxide (FTO) and Silver (Ag) is used as top and bottom contact. The impact of QD size and dot spacing on the key parameters of MAPbI3 QD-IBSC is illustrated throughout this paper. In order to identify the number of IB in a single regime, Schrödinger equation is solved as a function of host energy gap using Kronig–Penney model. The detailed balance limit assumptions with unity fill factor are applied to extract highest efficiency from the system. For any case, face centered cubic (FCC) crystal structure is assumed. The (100) crystal orientation is considered as charge carriers from n–region to p–region transport in this orientation. Major performance indicators of the device such as photocurrent intensity Jsc, open circuit voltage Voc and power conversion efficiency η have been delineated. Highest efficiency of 63% is attained for dot size of 4 nm and dot spacing of 1.5 nm.

Efficiency Study of PbTe/CdTe Core/Shell Quantum Dots Solar Cells

In this work we theoretically study how to optimize the efficiency of an intermediate band solar cell based on IV-VI PbTe/CdTe semiconductor materials. We focus our attention on how control structural parameters, such as the height and radius in cylindrical quantum dots and the radius in spherical quantum dots to obtain the inter and intraband transition energies that provide the highest efficiency values of the solar cell. The calculation of the energy levels, the selection rules for transitions energies were performed using the 4×4 k.p Kane-Dimmok Hamiltonian.