Influence of the precursor layer composition and deposition processes on the electronic quality of liquid phase crystallized silicon absorbers

Daniel Amkreutz, Natalie Preissler, Cham Thi-Trinh, Martina Trahms, Paul Sonntag, Rutger Schlatmann, Bernd Rech

Index: 10.1002/pip.2953

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Abstract

Liquid phase crystallization using line-shaped energy sources such as CW-diode lasers or electron beams has proven to form mc-Si layers on borosilicate or borosilicate/aluminosilicate glass that exhibit wafer equivalent grain sizes and electronic quality. In this work, we characterize the impact of the employed dielectric interlayer stack sandwiched between glass and absorber on the electronic quality. For this purpose, we investigate a large variety of test cell results achieved in the past on different interlayer stacks composed of silicon oxide, silicon nitride as well as silicon oxynitride deposited by means of plasma enhanced chemical vapour deposition or plasma oxidation and employ i(v), SunsVoc, quantum efficiency measurements, and photoluminescence imaging to assess the electronic properties of the crystallized absorbers. The results are compared with state-of the art interdigitated back-contact cells and literature values. Based on these findings, we conclude that at the present state of interlayer , the bulk quality imposes the limits in cell efficiency and investigates potential approaches to increase the bulk quality of LPC-Si absorbers. In this work, we summarize the influence of different interlayer materials on the electronic and morphological properties of liquid phase crystallized absorbers. We compare interdigitated back-contact solar cells made on these stacks and discuss approaches to further increase the overall cell performance by tackling bulk limitations.