Luminescence from Poly-Si Films and Its Application to Study Passivating-Contact Solar Cells
Hieu Nguyen1, Thien Truong1, Di Yan1, Christian Samundsett1, Rabin Basnet1, Mike Tebyetekerwa1, Harvey Guthrey2, Mowafak Al-Jassim2, Ziyuan Li3, lily Li3, Felipe Kremer4, Andres Cuevas1, Daniel Macdonald1
1Research School of Engineering, The Australian National University, Canberra, Australia
/2National Renewable Energy Laboratory, Golden, CO, United States
/3Department of Electronic Materials Engineering, the Australian National University, Canberra, Australia
/4Centre for Advanced Microscopy, the Australian National University, Canberra, Australia

In recent years, polycrystalline silicon (poly-Si) based passivating-contact solar cells have received tremendous attention from the solar research community due to its excellent surface passivation and high carrier conductivity. However, the poly-Si films are not transparent to all wavelengths of the solar spectrum. There is often some parasitic absorption in these films. From a different standpoint, as they absorb some light, they can luminesce. This phenomenon provides us with unique opportunities to investigate optoelectronic properties of the films in a fast, contactless, and nondestructive manner. In this work, for the first time, we report the luminescence phenomenon from poly-Si films used in passivating-contact solar cells. We then utilize this phenomenon to report a range of applications for solar cells including studies of carrier transport behaviors and hydrogenation inside the films.