Group IV Nanocrystals for Silicon Photovoltaics

Abstract

Silicon nanocrystals (nc-Si), have been shown to act as opto-electronic centers enabling light emission by carrier recombination, when precipitated in a silicon nitride (Si3N4) host. In this work, nc-Si and Germanium nanocrystals (nc-Ge) are studied in sputtered films of Si3N4 and SiGeN for application as tandem cell layers in a Si solar cell. The samples are annealed in a nitrogen gas and forming gas ambient, from 500 ºC to 900 ºC, to investigate the influence of temperature on photoluminescence and photoconductivity.

A Review on Ge Nanocrystals Embedded in SiO2 and High‐k Dielectrics

“…Elsewhere, similar PL bands were attributed to Si/Ge‐related defects . In further studies, no PL bands are observed, neither in the visible nor the infrared region.…”

“…Ge‐rich Si 3 N 4 films (GeSiN x ) were synthesized by MS Ge‐ion implantation and CVD . The annealing step to form the Ge nanocrystals is usually performed between 700 and 1000 °C.…”

“…The annealing step to form the Ge nanocrystals is usually performed between 700 and 1000 °C. Typical process gases are nitrogen, forming gas, and, in order to form SiON, oxygen…”

“…Ge nanocrystals in Si 3 N 4 were investigated as charge storage nodes in non‐volatile memory devices, as light emitters (PL), as absorption layer in solar cells and as light detectors . In the case of non‐volatile memories, Si 3 N 4 was used as blocking oxide and HfO 2 or SiO 2 or a combination of both as tunneling oxide.…”