The effect of embedded nanopillars on the built-in electric field of amorphous silicon p-i-n devices

In this work, we report on the experimental modification of the built-in electric field of a-Si:H p-i-n junctions, resulting from Ag nanopillars embedded within the intrinsic layer (i-layer). Increased open-circuit voltages, from J-V traces, and reduced charge transit-times, from time-of-flight (ToF) measurements, indicate that the built-in electric field within the i-layer is increased with respect to unstructured reference samples. Decreased short-circuit current density values coupled with competing diode J-V characteristics, however, indicate that the charge collection from the i-layer is significantly decreased for the nanopillar samples. Theoretical and functional analysis of the ToF data reaffirms both reduced charge-transit times and decreased charge collection, and is able to quantitatively confirm the enhanced built-in electric field of the nanopillar samples.