Enhancing silicon photovoltaics research via integrated circuit wafer engineering defect science experiences and industry/University Consortia

Experimental electrical property data on silicon grain boundaries (GBs) are reported on a unique sample set consisting of direct silicon bonded (110)/(100) hybrid orientation wafers using C-V, I-V, and MOS capacitance transient techniques. For the relatively clean interfacial bonded GB, the density of GB states N_T is on the order of 10¹² eV^-1cm^-2, and the charge neutral level is at ~0.53 eV from the valance band. N_T increased to over 2×10¹³ eV^-1cm^-2 after Fe contamination, but was reduced to ~1×10¹³eV^-1cm^-2 after a hydrogenation treatment. The charge neutral level shifted towards the conduction band after Fe contamination; however, this could be reversed by hydrogenation. The electron emission rate from the GB donor states was about two orders of magnitude larger than their corresponding hole emission rate.