Changes in the serial resistance Of a- Si, a-/μc-Si and mono-crystalline PV modules during the year
The changes in the serial resistance Rs of amorphous (a- Si) and amorphous/microcrystalline (a-/μc-Si) tandem silicon-based solar cells is a criterion to analyze the process of light -induced degradation and thermal healing of defects described by the Staebler - Wronski effect. Measurements under laboratory conditions show that the serial resistance increases during the light-induced degradation. Our annual measurement of a- Si, a-/μc-Si and mono-crystalline (c-Si) solar cells under field test conditions will verify this and it will improve the possibility of predicting the behavior of thin-film silicon photovoltaic cells. For a year, the complete current-voltage curve was measured every minute, recorded and analyzed. This data has been transferred into the equivalent circuit diagram for solar cells.
Study of forward I‐V plot for Schottky diodes with high series resistance
The current‐voltage characteristics for Schottky barrier diodes with series resistance are discussed. It is shown that by using Norde’s function F(V)=V/2−(kT/q)ln(I/SAT2) at two different temperatures, barrier height, n‐value or ideality factor, and series resistance can be determined even in the case 1
Investigation of the double exponential in the current-voltage characteristics of silicon solar cells. [proton irradiation effects on ATS 1 cells]
A theoretical analysis is presented of certain peculiarities of the current-voltage characteristics of silicon solar cells, involving high values of the empirical constant A in the diode equation for a p-n junction. An attempt was made in a lab experiment to demonstrate that the saturation current which is associated with the exponential term qV/A2kT of the I-V characteristic, with A2 roughly equal to 2, originates in the space charge region and that it can be increased, as observed on ATS-1 cells, by the introduction of additional defects through low energy proton irradiation. It was shown that the proton irradiation introduces defects into the space charge region which give rise to a recombination current from this region, although the I-V characteristic is, in this case, dominated by an exponential term which has A = 1.