Breakdown of temperature sensitivity of silicon solar cells by simulation input parameters

Abstract

As the electrical characteristics of silicon solar cells depend significantly on their temperature T of operation, it is vital to analyze and understand the contributions of the various cell properties in detail in order to optimize silicon solar cells for improved energy output in realistic operation conditions. Within a detailed electro-optical solar cell model, as used for numerical device simulation, accounting for full T-dependence of all cell properties has rarely been attempted to date. This is mainly due to the T-dependence of simulation input parameters not being well known or difficult to measure, resulting in unknown inaccuracy for T-dependent device simulations. This study improves previous T-dependent device models by including the T-dependence of injection-dependent bulk lifetime τbulk as well as lumped skin surface recombination parameter J0,skin, which are commonly assumed T-independent, for the “lumped skin” multidimensional device model employed by the software Quokka3. With this improved T-dependent device model, we present a comprehensive breakdown of a typical PERC cell's temperature sensitivity by each simulation input parameter. As figures of merit we simulate T-coefficients of IV-parameters, as well as energy yields. Overall, we find that the relative influence of the T-dependence of τbulk and J0,skin is rather small for our examples, clarifying that for modeling typical PERC cells neglecting of their T-dependence does not result in a substantial error. Nonetheless, T-dependency of the bulk material has been found to vary significantly. Also, there remains substantial uncertainty of actual T-dependence of recombination at contacts and lowly doped surfaces worth of further investigations.