Today, the global world is concerned about the rapidly depleting fossil fuel reserves and the serious consequences of these fossil fuels on the environment have prompted an increase in interest in the development of clean and renewable energy sources. Currently, numerous inexhaustible power options, such as solar power, wind power, biomass, etc., are being implemented in the market. However, solar energy is abundant in our environment and is a safe and clean source of energy. As a result, considerable efforts were made in the development of advanced photovoltaic technology to achieve higher power conversion efficiency (PCE) and lower processing costs. In the last 10 years, technological advancements in organic-inorganic halide perovskite solar cells (PSCs) have demonstrated increased absorption coefficient, extended carrier-diffusion length, [1,2] improved carrier mobility, [3,4] ease of fabrication in a variety of areas, and the ability to meet photovoltaic application and space application requirements. [5][6][7] The Pbbased PSC device was initially developed by Kojima et al., who pioneered PSC research and reported a PCE of up to 3.8%. [8] Numerous studies conducted over the last decade have focused on Pb-based PSC devices as a light-absorbing material and have achieved an efficiency of approximately 25.2% in 2019. [9][10][11] The conventional formula of this device structure is ABX 3 which contains an organic methyl ammonium (CH 3 NH 3 þ ) [12] or formamidinium (NH ¼ CHNH 3 þ ) ion [13] and an inorganic element such as Pb, Ge, or Sn. [14,15] Despite its increased efficiency, the problem with this structure is its instability and toxicity, which prevents it from being used commercially. [16] To overcome these difficulties, germanium (Ge) can be used as a perovskite material to provide analogous optoelectronic properties to the PSC. Furthermore, Ge is a far superior contender in terms of stability and environmental friendliness. [17,18] Ge-based PSC devices are more thermally stable in the active layer than lead-based PSC devices, resulting in less material deterioration. [19,20] In the past, different researchers have synthesized Ge-based PSC devices. In 2013, Stoumpos et al., discovered unique nonlinear optical characteristics and a very unconventional structure in the Ge-based perovskite. [21] Following the synthesis of lead-free Ge perovskite materials in 2015, Krishnamoorthy et al. noticed that this class of photovoltaic materials showed a high potential for use in solar panels. [22] Recently, Kanoun et al. and Lakhdar et al. demonstrated computational analysis of the germanium structure of PSC devices, demonstrating an increase in the device's efficacy. [17,23] While researchers have demonstrated an increase in efficiency, the solar cell's current density ( J sc ) is extremely low, and a higher current density is required for the future of Ge-based perovskite solar cells (GBPSCs) with increased efficacy too.The GBPSC is constructed with an absorbance layer of germanium perovskite sandwiched between the ...

A thin film based Cadmium Telluride photovoltaic cell is becoming highly competitive in the electric power industry. The major problem with the CdTe photovoltaic cell is the large barrier height behind the rear contact surface that prevents the solar cell to reach notional efficiency of 32%. A buffer layer is added to get a better result in terms of efficiency by reducing the valence barrier height at the rear contact surface of the CdTe photovoltaic cell. This manuscript presents the numerical simulation and optimization of ITO/TiO2/CdS/CdTe/MoS2/Au original photovoltaic cell structure using SCAPS 1D software. Furthermore, the effect of CdTe thickness, defect density, and acceptor density of MoS2 layer is discussed. Simulation results show that with the optimization of layer and parameters of the photovoltaic cell, efficacy of the p hotovoltaic cell is quite improved. With optimized solar cell, efficiency is improved to 26.49%, Voc = 1.141 V, Jsc = 27.690 mA/cm2, FF = 83.80% as compared to basic CdTe model which has an efficiency of 21.69%.

This article discusses the numerical analysis of heterojunction photovoltaic cells based on cadmium telluride (CdTe) using the SCAPS‐1D software. A novel glass/FTO/SnO2/CdS/interdiffusion/CdTe/SnS2/Se photovoltaic cell design is proposed for investigation. Additionally, the effect of thickness variation in the p‐type CdTe film, thickness variation in the interdiffusion layer, defect density in the CdTe film, defect density in the interdiffusion layer, and acceptor concentration in the CdTe layer is studied in order to improve the photovoltaic cell's efficiency. The study determines an optimal thickness of 1 and 0.6 μm for the CdTe and interdiffusion layers, respectively, a defect density of 1 × 1014 cm−3 for the CdTe film and interdiffusion region, an interface defect density of 1 × 1010 cm−3 between CdTe/interdiffusion, SnS2/CdTe, and CdS/interdiffusion, and an acceptor concentration value of 8.5 × 1015 cm−3. The optimized CdTe photovoltaic cell structure with current density (Jsc) = 30.003 mA cm−2, open‐circuit voltage (Voc) = 1.061 V, and fill factor (FF) = 88.10% achieves a 28.07% efficiency, compared to the baseline CdTe photovoltaic cell structure with a 23.01% efficiency.

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Dielectric metasurfaces with unique possibilities of manipulating light-matter interaction lead to new insights in exploring spontaneous emission control using single quantum emitters. Here, we study the stacked metasurfaces in one- (1D) and two-dimensions (2D) to enhance the emission rate of a single quantum emitter using the associated optical resonances. The 1D structures with stacked bilayers are investigated to exhibit Tamm plasmon resonance optimized at the zero phonon line (ZPL) of the negative nitrogen-vacancy (NV-) center. The 2D stacked metasurface comprising of two-slots silicon nano-disks is studied for the Kerker condition at ZPL wavelength. The far-field radiation plots for the 1D and 2D stacked metasurfaces show an increased extraction efficiency rate for the NV- center at ZPL wavelength that reciprocates the localized electric field intensity. The modified local density of optical states results in large Purcell enhancement of 3.8 times and 25 times for the single NV- center integrated with 1D and 2D stacked metasurface, respectively. These results have implications in exploring stacked metasurfaces for applications such as single photon generation and CMOS compatible light sources for on-demand chip integration.