Concentrator multijunction solar cell characteristics under variable intensity and temperature

Abstract

The performance of multijunction solar cells has been measured over a range of temperatures and illumination intensities. Temperature coefficients have been extracted for three-junction cell designs that are in production and under development. A simple diode model is applied to the three-junction performance as a means to predict performance under operating conditions outside the test range. These data may be useful in guiding the future optimization of concentrator solar cells and systems.

Temperature of solar cells with regard to photoactive and non-photoactive light absorption in concentrator PV modules

“…It is known that, at the fixed density of the current generated in a cell, the V OC = f(T) dependence is, practically, a linear function in the near to room temperature range [2]. For this reason, one can write that: Figure 2, where the V OC MPP value is measured during a short time period just after switching-off the external load, and the T ext MPP value -in the period of achieving the system thermal balance before this switching.…”

“…An indicator for success in the managements is a low overheating temperature of the solar cells (SCs) with respect to the ambient temperature in operational conditions at electrical loading in the maximum power point (MPP) of the I-V curve. The open circuit voltage (V OC ) is a good indicator of cell temperature, if the temperature coefficient for it is preliminary measured in the pulse regime of illumination at a given photocurrent density [2]. Unfortunately, the V OC value as a temperature indicator gives substantially higher temperature in MPP of a highly efficient cell, when a considerable part of power is dissipated in the external load [3].…”

Concentrated photovoltaics, a case study

“…Concentrated photovoltaics modules use 3J solar cells, whose temperature coefficient is almost one order of magnitude lower (−0.04%/K) [3]. They are thus performing very well also in hot climates, even using passive (air) cooling [4,5].…”

Concentrated PhotoVoltaics (CPV): Is it a real opportunity?

“…5 [7]. These parameters have some dependences on concentration ratio and cell's temperature that must be taken into account when designing a concentrator [8].…”

“…-When designing a concentrated photovoltaics module, great attention must be paid to the thermal management: thermal management of CPV modules is one of the most important parts of its technology: the efficiency of the solar cells used decreases linearly increasing its temperature, at a rate of −0.06%/K, due to electron-phonon interactions [9]. As in any solar cell, the efficiency of the cell is strongly dependent on the cell's temperature [8]. The open-circuit voltage of the 3J solar cell decreases at a rate of 01015-p.8 −4.5 mV/K, and the short-circuit current increases at a rate of +4.7 mA/K (over a surface of 1 cm 2 ).…”