Shafi Ullah

Enhancement of the conversion efficiency of thin film kesterite solar cell

C u 2 ZnSn S 4 ( CZTS ) is a non-toxic earth abundant material and a promising quaternary semiconductor compound of groups I − I I − I V − V I having a kesterite symmetrical structure. Due to its optimum direct bandgap, it has been considered as a suitable material for absorber layers for photovoltaic cell applications. This paper presents the numerical simulation and modeling of CZTS based thin film kesterite photovoltaic cells using SCAP-1D software. The influence of device parameters such as the carrier concentration, thickness, densities of absorber, buffer and window layers, defect densities and the temperature effect on the performance of the Z n O / C d S / CZTS / M o photovoltaic cell structure are analyzed. Defect densities are added to the absorber layer and the interface between the buffer layer and the absorber layer. This type of solar cell does not comprise any toxic material and can lead to non-toxic thin film photovoltaic cells with outstanding optical properties. In this work, promising optimized results had been achieved with a conversion efficiency of 23.72%, a fill factor of 82.54%, a short-circuit current ( J s c ) of 44.87 mA / cm 2, and an open circuit voltage ( V o c ) of 0.64V. C u 2 ZnSn S 4 ( CZTS ) is a non-toxic earth abundant material and a promising quaternary semiconductor compound of groups I − I I − I V − V I having a kesterite symmetrical structure. Due to its optimum direct bandgap, it has been considered as a suitable material for absorber layers for photovoltaic cell applications. This paper presents the numerical simulation and modeling of CZTS based thin film kesterite photovoltaic cells using SCAP-1D software. The influence of device parameters such as the carrier concentration, thickness, densities of absorber, buffer and window layers, defect densities and the temperature effect on the performance of the Z n O / C d S / CZTS / M o photovoltaic cell structure are analyzed. Defect densities are added to the absorber layer and the interface between the buffer layer and the absorber layer. This type of solar cell does not comprise any toxic material and can lead to non-toxic thin film photovoltaic cells with outstanding optical properties. In this wor...

Fabrication of Cd 1−x Zn x S buffer layer deposited by Chemical Bath Deposition for photovoltaic applications

Cd1−xZnxS films suitable for solar cell photovoltaic applications have been deposited by chemical bath deposition (CBD) on to indium tin oxide (ITO) coated glass substrates. An aqueous solution containing cadmium sulfide, zinc sulfide and thiourea were used as sources of Cd+2, Zn+2, and S−2, respectively. Triethenolamine was used as complexing agent to control the Cd+2 and Zn+2 ions concentrations and ammonia to adjust the pH of the solution. The temperature of the bath was kept at 70 °C. The as deposited films are well adherent, homogeneous and free from pinholes. The incorporation of Zn in CdS was found to be dependent on the annealing temperature. The structure of the CdZnS thin films, as observed by X-ray diffraction, was polycrystalline with hexagonal structure. Several diffraction peaks corresponding to crystallographic planes (100), (002), (102), (110) (103) and (004) were observed. According to energy dispersive spectroscopy (EDS) the films are non-stoichiometric due to a deficit of sulfur, which becomes more important as the Zn content increases. The absorption edge shifts towards the lower wavelength region and hence the band gap of the films increases as the Zn content increases. The values of the absorption edge are found to vary from (Eg ∼ 2.42 eV) for the CdS film and (Eg ∼ 3.30 eV) for the ZnS film. Cd1−xZnxS thin films can be useful as buffer and window layers in Cu(In,Ga)Se2 and Cadmium telluride (CdTe) thin films solar cells due to ability to tune the band gap through the Zn/Cd ratio present in the chemical bath.

Effect of Cu2O hole transport layer and improved minority carrier life time on the efficiency enhancement of Cu2NiSnS4 based experimental solar cell

C u 2 NiSn S 4 is a non-toxic earth abundant material and a promising quaternary semiconductor compound. Due to its optimum direct band gap, it has been considered as a suitable absorber material for photovoltaic cells. It is a conspicuous and suitable class of material for the fabrication of low cost and high efficiency thin film devices. This paper presents numerical modeling for the efficiency enhancement of C u 2 NiSn S 4 based experimental photovoltaic cells. In this work, the experimental cell results were reproduced in the SCAPS software. These simulated results are validated and compared with the experimental reference cell. C u 2 O as the hole transport layer is also proposed for further efficiency enhancement of the photovoltaic cell. After optimization of cell parameters, the power conversion efficiency of an optimized device is increased up to 4.60%. By applying the hole transport layer and analyzing the minority carrier life time, the conversion efficiency increases up to 10.35%. This work presents a novel concept in numerical modeling by analyzing the experimental solar cell, which will categorically offer new directions for the fabrication of high efficiency photovoltaic devices. C u 2 NiSn S 4 is a non-toxic earth abundant material and a promising quaternary semiconductor compound. Due to its optimum direct band gap, it has been considered as a suitable absorber material for photovoltaic cells. It is a conspicuous and suitable class of material for the fabrication of low cost and high efficiency thin film devices. This paper presents numerical modeling for the efficiency enhancement of C u 2 NiSn S 4 based experimental photovoltaic cells. In this work, the experimental cell results were reproduced in the SCAPS software. These simulated results are validated and compared with the experimental reference cell. C u 2 O as the hole transport layer is also proposed for further efficiency enhancement of the photovoltaic cell. After optimization of cell parameters, the power conversion efficiency of an optimized device is increased up to 4.60%. By applying the hole transport layer and analyzing the minority carrier life time, the conversion efficiency increases up to...

Baseline of numerical simulations for ZnTe based thin-film solar cells.

Numerical modelling of photovoltaic solar cells is an important strategy to test the viability of proposed physical structures and their performance. This article introduces the concept of numerical simulation and explain the relevant physical models for the inside physical phenomenon like generation, recombination and transport of charge carriers (holes and electrons) in photovoltaic materials. This will made with essential input parameters, to have consistent and acceptable results. It is extremely useful to have a common baseline or starting point for researchers working on the same problem under different conditions irrespective of the place, group, research environment and tools/software used. The numerical work, hence produces results for fitting of modelling output to experimental results, predicting the effect of changes in material properties and geometry of cell performance and testing the viability of proposed physical device. A case-study for baseline parameter sets are presented that describes ZnTe based thin-film solar cells consist in ZnO/n-CdS/p-ZnTe in a substrate sequence. This model can be used as a baseline for more complicated models and will help photovoltaic researchers for enhancing the efficiency and reduction the costs in

Baseline of numerical simulations for ZnTe based thin-film solar cells

/Wp of photovoltaic devices.

Numerical modeling baseline for high efficiency (Cu 2 FeSnS 4 ) CFTS based thin film kesterite solar cell

Numerical modelling of photovoltaic solar cells is an important strategy to test the viability of proposed physical structures and their performance. This article introduces the concept of numerical simulation and explain the relevant physical models for the inside physical phenomenon like generation, recombination and transport of charge carriers (holes and electrons) in photovoltaic materials. This will made with essential input parameters, to have consistent and acceptable results. It is extremely useful to have a common baseline or starting point for researchers working on the same problem under different conditions irrespective of the place, group, research environment and tools/software used. The numerical work, hence produces results for fitting of modelling output to experimental results, predicting the effect of changes in material properties and geometry of cell performance and testing the viability of proposed physical device. A case-study for baseline parameter sets are presented that describes ZnTe based thin-film solar cells consist in ZnO/n-CdS/p-ZnTe in a substrate sequence. This model can be used as a baseline for more complicated models and will help photovoltaic researchers for enhancing the efficiency and reduction the costs in

Effect of CZTSe BSF and minority carrier life time on the efficiency enhancement of CZTS kesterite solar cell

/Wp of photovoltaic devices.