Structure of the Dark J-V Characteristic of Multijunction Solar Cells and Their Efficiency

Autor: Kalinovsky, V.S., Evstropov, V., Kalyuzhnyy, N., Lantratov, V., Mintairov, S.A., Andreev, V.M.
Jazyk: angličtina
Rok vydání: 2008
Předmět:
DOI: 10.4229/23rdeupvsec2008-1dv.3.5
Popis: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 773-776
The dark resistanceless (not accounting for the series resistance) current-voltage characteristic of a multijunction (MJ) and singlejunction solar cells (SC’s) determines their efficiencies. This characteristic for a MJ SC consists of a set of exponential portions as for a singlejunction one. This gives grounds to introduce a definition of a resultant p-n junction simulating a MJ SC with resultant diode coefficients and preexponential factors on each portion. An equation correlating the efficiency h and the generated current density Jg has been obtained with and without accounting for the series resistance. For the InGaP, GaAs p-n junctions and InGaP/GaAs tandem, dark resistanceless current-voltage characteristics in the current density range of (10-5 – 101) A/cm2 has been obtained. For the InGaP/GaAs tandem on the portion of the recombination origin (the resultant diode coefficient A=4), the resultant preexponential factor J0r » 3 10-13A/cm2; on the portion of the diffusion (A=2) origin J0d » 2 10-23A/cm2. Using the equation obtained, the h - Jg characteristic has been calculated and plotted. For the InGaP/GaAs tandem, this characteristic fits well to the experimental one. The results shown that, for the tandem InGaP/GaAs solar cells at the generated currents density Jg » (10-2-100) A/cm2, the contribution of the recombination component should be accounted for.
Databáze: OpenAIRE