The influence of factors on the characteristics and performance of photovoltaic cells can be studied experimentally. For cell design, computer simulations are a useful and inexpensive tool. An example of a program in which current-voltage characteristics can be simulated for photovoltaic cells is PC1D. PC1D is a simple program provided free of charge by the University of New South Wales (Sydney). The program solves coupled nonlinear equations for quasi-uniform electron and hole transport of semiconductor devices.
Version 5.9 of the program was used in the simulations presented below. PC1D contains library files with parameters of crystalline semiconductors used in photovoltaic technology, such as silicon, germanium, gallium arsenide, indium phosphorite, etc. (see Fig. 1, Fig. 2 ) [1], [2].

The simulation was performed for cells with an area of \( 100 cm^{2} \) and thickness \( 300 \mu m \). The properties (absorption spectrum, reflectance, energy gap, charge mobility, etc.) were imported from the program's material library. The simulation assumes illumination of the cell with the AM1.5 spectrum, with a light intensity of 0.1 \( \frac{W}{cm^{2}} \), at 300 K.

To check the influence of light intensity on the characteristics and parameters of the cell, simulations were carried out for a silicon cell at four different light intensities: 0.1 \( \frac{W} {m^{2}} \), 0.05 \( \frac{W} {m^{2}} \), 0.01 \( \frac{W} {m^{2}} \), 0.001 \( \frac{W}{m^{2}} \). The AM1.5 spectrum was used in the simulation. The current-voltage characteristics and power-voltage dependence are shown in Fig. 3. In the figure, the red lines indicate the current-voltage characteristics and the green lines indicate the power-voltage dependence for a Si silicon cell at radiant power a) 0.1 \( \frac{W}{cm^{2}} \) b) 0.05 \( \frac{W}{cm^{2}} \) c) 0.01 \( \frac{W} {cm^{2}} \) d) 0.001 \( \frac{W}{m^{2}} \). A reduction in the intensity of the radiation incident on the cell results in a decrease in the value of \( I_{sc}, V_{oc} \) and output power \( P_{out} \) and thus the performance of the cell.

The cell parameters are collected and shown in Fig. 4.

Afterwards, to determine the effect of temperature alone on the performance of the silicon cell, a simulation was carried out in the temperature range from \( -30_{}^{o}\textrm{C} \) to \( 50_{}^{o}\textrm{C} \). As shown in Fig. 5, the efficiency decreases linearly with increasing temperature. In the program, temperature can be specified in Kelvin or degrees Celsius. The programme's algorithm takes into account the effect of temperature on carrier mobility, surface and volume recombination.

The decreasing linear dependence of cell efficiency on temperature obtained from the simulation is in agreement with the results of tests carried out on real photovoltaic cells (see Chapter: 8.3 Temperature dependence of cell parameters ).