The truncated-pyramid MIS inversion-layer solar cell: a comprehensive analysis

Abstract

Metal–insulator–semiconductor inversion‐layer (MISIL) solar cells are of significant interest because of their simple fabrication process. In this work a comprehensive analysis of the improved front surface design of truncated‐pyramid MISIL silicon solar cells is presented. This analysis reveals the two most important effects that have led to an increase in the open‐circuit voltage of more than 50 mV. Firstly, passivation of the non‐grid area at the front surface is optimized to meet the special requirements of MISIL solar cells. Secondly, the MIS contact is investigated very thoroughly. This includes the recombination properties of the contact and the current transport via the MIS contact. The results of this investigation show that the contact area can be reduced without an increase in the series resistance of the MISIL solar cells and therefore the recombination losses at the metal contacts are reduced. As a result of these improvements, independently confirmed 1‐sun efficiencies above 17% are achieved with truncated‐pyramid MISIL solar cells. © 1998 John Wiley & Sons, Ltd.

Molybdenum oxide MoOx: A versatile hole contact for silicon solar cells

“…Whilst the use of the TLM procedure on heavily diffused surfaces is well accepted, 21 its application to low resistivity wafers with a surface inversion layer has only been explored briefly. 22,23 In this approach, we have assumed that current flows are confined to the inversion layer. The sheet resistance of this inversion layer is also measurable by the TLM.…”

“…The R IL $ 12 kX/ٗ measured here is lower than the values reported for inversion layer solar cells, suggesting a higher concentration of holes near the surface. 22,23 An equivalent inversion layer charge can be calculated from R IL using an average surface hole mobility of 80 cm 2 /V, taken from the previous studies on MOSFET devices. 26 From this charge, a corresponding potential at the c-Si surface w s can be calculated by assuming Fermi-Dirac statistics.…”