摘要
Light trapping photonic crystal(PhC)patterns on the surface of Si solar cells provides a novel opportunity to approach the theoretical efficiency limit of 32.3%,for light-to-electrical power conversion with a single junction cell.This is beyond the efficiency limit implied by the Lambertian limit of ray trapping~29%.The interference and slow light effects are harnessed for collecting light even at the long wavelengths near the Si band-gap.We compare two different methods for surface patterning,that can be extended to large area surface patterning:1)laser direct write and 2)step-&-repeat 5×reduction projection lithography.Large area throughput limitations of these methods are compared with the established elec-tron beam lithography(EBL)route,which is conventionally utilised but much slower than the presented methods.Spec-tral characterisation of the PhC light trapping is compared for samples fabricated by different methods.Reflectance of Si etched via laser patterned mask was~7%at visible wavelengths and was comparable with Si patterned via EBL made mask.The later pattern showed a stronger absorbance than the Lambertian limit6.
基金
project support by Nano-Processing Facility (NPF), AIST, Tsukuba, Japan where we were granted access to photo-lithography stepper
ARC DP190103284 "Photonic crystals: the key to breaking the silicon-solar cell efficiency barrier" project
the visiting professor program at the Institute of Advanced Sciences at Yokohama National University (2018-20)
Nanotechnology Ambassador fellowship at MCN (2012-19)
作者简介
Jovan Maksimovic,These authors contributed equally to this work;Jingwen Hu,These authors contributed equally to this work;Correspondence:Sajeev John,E-mail:John@physics.utoronto.ca;Correspondence:Saulius Juodkazis,E-mail:SJuodkazis@swin.edu.au。
