Epitaxial thin-film Si solar cells

Efficiency (>15%) for thin‐film epitaxial silicon solar cells on 70 cm2 area offspec silicon substrate using porous silicon segmented mirrors

“…The projected manufacturing cost of such low cost substrates in a coming year will be 5 $/kg, much below even from dropping prices anticipated stabilized solar grade feedstock costs of $20-30 $/kg [1]. Based on such feedstock cost and assuming further reduction of the amount of crystalline Si/W p with a rate of 5%/year, the cost of bulk crystalline Si solar cell modules would be in the range of $1Á2/W p , with industrial cell efficiencies of nearly 20%.…”

“…Thin-film epitaxial Si solar cells, often referred as wafer equivalent (EpiWE), are a promising future alternative to bulk Si solar cells since the active epitaxial layer can be deposited on low quality silicon substrates, resulting in reduced costs and energy pay-back time [1]. The projected manufacturing cost of such low cost substrates in a coming year will be 5 $/kg, much below even from dropping prices anticipated stabilized solar grade feedstock costs of $20-30 $/kg [1].…”

Introduction

“…The same crystallographic perfection of thin films applies to semiconductors for multilayer heterostructures for photovoltaic cells 17 and, as is more recently recognized, for photoelectrochemical cells. 18 Therefore, not only the field of computer technology but also energy technology benefitted, ultimately, from van der Merwe's seminal work.…”

In situ annealing and high-rate silicon epitaxy on porous silicon by mesoplasma process

“…The results show that annealing for a few seconds using Ar-H 2 mesoplasma has significant effects on the porous Si substrate, similar to those obtained by convention annealing in H 2 ambient for >30 min. In this study, the epitaxial Si films deposited at a rate of 350 nm=s on the annealed porous Si substrate from SiH 4 show properties identical to those of the films deposited on a polished Si wafer.…”