Impact of bulk impurity contamination on the performance of high‐efficiency n‐type silicon solar cells

Abstract

The experimental variation of wafer thickness and resistivity at device level combined with a comprehensive device simulation study allows the identification of dominating recombinationinduced power loss mechanisms in high-efficiency n-type silicon solar cells (A. Richter et al, Sol. Energy Mater. Sol. Cells 173, p. 96, 2017). Under the assumption of specific Shockley-Read-Hall (SRH) recombination parameters, impurity recombination within the silicon bulk was identified as one main source for efficiency losses particularly for solar cells made of high-resistivity silicon. In this work, we extend that analysis approach focusing on the SRH recombination parameters in order to investigate whether certain properties of these recombination-active impurities can be identified using this kind of simulation-based analysis. Reported SRH recombination parameters of various common impurities (eg, Fe, Cr, or Ni) were considered. It was found that a dominating role of certain impurities as Cu, Au, Co, or Zn can be excluded. A general simulation study as a function of the fundamental SRH recombination parameters allowed us to reduce the possible SRH parameters significantly in particular of the capture cross-section ratio of electrons and holes. These results demonstrate that our analysis approach, which combines an experimental variation of wafer thickness and resistivity with a comprehensive device simulation, can provide deep insights into the solar cells loss mechanisms. In particular, the conclusions regarding SRH recombination are of importance for solar cells made of n-type silicon as there are no meta-stable impurity states formed that would allow a direct identification of impurity recombination-related power loss as reported for p-type Si.

Application of n‐Polysilicon Rear Emitter for High‐Efficiency p‐TOPCon Solar Cells

“…Moreover, theoretical simulation studies further provide equitable insight into a silicon solar cell with a polysiliconbased passivated contact, comprising the selective collection of charge carriers, [25,26] surface passivation, [27,28] pinhole-assisted transportation, [29,30] screen printing, [27] wafer parameters, [31,22,23] and impurity contamination. [32] Typically, silicon solar cells based on passivated contacts with polysilicon have emerged as competing contenders for high conversion efficiency owing to their easy construction and superior performance. Consequently, one of the crucial areas of silicon photovoltaics research is the polysilicon passivated contact.…”

“…Moreover, theoretical simulation studies further provide equitable insight into a silicon solar cell with a polysilicon‐based passivated contact, comprising the selective collection of charge carriers, [ 25,26 ] surface passivation, [ 27,28 ] pinhole‐assisted transportation, [ 29,30 ] screen printing, [ 27 ] wafer parameters, [ 31,22,23 ] and impurity contamination. [ 32 ]…”

Optical simulation of CsPbI3/TOPCon tandem solar cells with advanced light management

“…To date, the efficiencies of champion CsPbI 3 solar cell and n-type TOPCon solar cells are 20.37% and 25.8% with V OC of 1.198 V and 0.724 V, respectively. [16,48] We used these measured V oc and the simulated J G as input parameters to calculate the potential PCE of the CsPbI 3 /TOPCon TSC. The model used to calculate the PCE is provided in Fig.…”

Photogenerated Electrical Fields for Biomedical Applications

“…Electrical phototransduction is the process through which photons are converted into electrical signals. For instance, inorganic semiconductors are exploited for their capacity to convert light into electrons flow by means of their P-N junction (Richter et al, 2018 ). However, their rigid nature, together with their poor biocompatibility has generated a major attention toward their organic counterparts for biomedical applications.…”