Analysis of cooling load on commercial building in UAE climate using building integrated photovoltaic façade system

The dark current–voltage of the Au/n+(a-Si:H)/n(SiGe)/p(c-Si)/Ag heterojunction structure have been investigated in order to determinate the electrical conduction mechanisms. The forward current at different temperatures was found to be increased exponentially at low applied voltage $$(V \le 0.4 {\text{V}})$$
 indicating that the conduction mechanism of the diode was controlled by the thermionic emission mechanism. While, at bias voltages higher than 0.5 V, the results obtained show that the carriers conduction was described by the space charge limited current mechanism. The effect of front surface field (FSF) on the photovoltaic parameters of Au/n+ (a-Si:H)/n(SiGe)/p(c-Si) heterojunction solar cell is studied. The experimental results obtained yielded to an improvement of about 50 mV for the open-circuit voltage, 1.1 mA cm−2 for the short-circuit current density, and about 1% for the cell efficiency compared to the conventional cell i.e. without a-Si:H thin layer (FSF).

Electrical transport mechanisms in amorphous silicon/crystalline silicon germanium heterojunction solar cell: impact of passivation layer in conversion efficiency

Impact of series and shunt resistances in amorphous silicon thin film solar cells

https://scholars.cityu.edu.hk/files/78208128/1_s2.0_S2214157X19304083_main.pdf

Risk priority number for understanding the severity of photovoltaic failure modes and their impacts on performance degradation

We present a new approach based on the multi-trench technique to improve the electrical performances, which are the fill factor and the electrical efficiency. The key idea behind this approach is to introduce a new multi-trench region in the intrinsic layer, in order to modulate the total resistance of the solar cell. Based on 2-D numerical investigation and optimization of amorphous SiGe double-junction (a-Si:H/a-SiGe:H) thin film solar cells, in the present paper numerical models of electrical and optical parameters are developed to explain the impact of the multi-trench technique on the improvement of the double-junction solar cell electrical behavior for high performance photovoltaic applications. In this context, electrical characteristics of the proposed design are analyzed and compared with conventional amorphous silicon double-junction thin-film solar cells.

Numerical investigation of a double-junction a:SiGe thin-film solar cell including the multi-trench region

An important requirement for a very fast spectral response measurement system is the simultaneous illumination of the solar cell at multiple well defined wavelengths. Nowadays this can be done by means of light emitting diodes (LEDs) available for a multitude of wavelengths. For the purpose to measure the spectral response (SR) of amorphous silicon solar cells a detailed characterization of LEDs emitting in the wavelength range from 300 nm to 800 nm was performed. In the here developed equipment the LED illumination is modulated in the frequency range from 100 Hz to 200 Hz and the current generated by each LED is analyzed by a Fast Fourier Transform (FFT) to determine the current component corresponding to each wavelength. The equipment provides a signal to noise ratio of 2–4 orders of magnitude for individual wavelengths resulting in a precise measurement of the SR over the whole wavelength range. The difference of the short circuit current determined from the SR is less than 1% in comparison to a conventional system with monochromator.

Development of a very fast spectral response measurement system for analysis of hydrogenated amorphous silicon solar cells and modules

Simulation data of the performance of amorphous silicon (a-Si:H) thin film solar cells using the software package Sentaurus TCAD (Synopsis Inc) are presented The Sentaurus software is configured with standard theoretical models describing eg the density of states in the mobility gap of a-Si:H, generation/recombination statistics, optical data of a-Si:H thin films etc to calculate illuminated current voltage curves and the respective spectral response for the initial and degraded state of the solar cell For the selected physical properties of the solar cell the simulation data predicts a maximum of the efficiency for an intrinsic a-Si:H layer thickness between 200–250 nm Furthermore, a guideline for the optimization of the p-doped layer thickness and the doping concentration is given

Simulation of the effect of p-layer properties on the electrical behaviour of a-Si:H thin film solar cells

Simulation data of the performance of amorphous hydrogenated silicon (a-Si:H) thin film solar cells using the software package Sentaurus TCAD (Synopsis Inc) are presented. The Sentaurus software is configured with standard theoretical models describing e. g. the density of states in the mobility gap of a-Si:H, generation/recombination statistics, optical data of a-Si:H thin films, etc. to calculate illuminated current voltage curves and the respective spectral response for the initial and degraded state of solar cell. The study of the temperature dependence of the electrical parameters of solar cell is realized. The simulations results were compared with experimental data measured in T-Solar laboratory obtaining a good coincidence.

Simulation of the temperature dependence of a-Si:H solar cell current-voltage characteristics

Nowadays it is possible to built a very fast spectral response (VFSR) measurement system by illuminating simultaneously the solar cell at multiple well defined wavelengths. This can be done by means of light emitting diodes (LEDs) available for a multitude of wavelengths, operating at different stimulation frequencies and analysis of the Fourier Transform of the generated solar cell current. For the purpose to measure the spectral response (SR) of silicon thin film solar cells a detailed characterization of LEDs emitting in the wavelength range from 300 nm to 1000 nm was performed. A VFSR equipment has been built implementing a selection of these LEDs and the difference of the short circuit current density (Jsc) determined from the SR with the VFSR results in about 1.8% in comparison to a conventional SR system with monochromator and lock-in amplifier technology. We have performed Jsc mappings in mini modules 10 cm × 10 cm with the VFSR system with the aim to show the potential and obstacles to perform Jsc mappings.

J. A. Rodriguez

Papers

Impact of series and shunt resistances in amorphous silicon thin film solar cells

Development of a very fast spectral response measurement system for analysis of hydrogenated amorphous silicon solar cells and modules

Simulation of the effect of p-layer properties on the electrical behaviour of a-Si:H thin film solar cells

Simulation of the temperature dependence of a-Si:H solar cell current-voltage characteristics

Development of a very fast spectral response measurement system for silicon thin film modules