Conformal coating of amorphous silicon and germanium by high pressure chemical vapor deposition for photovoltaic fabrics

Xiaoyu Ji,Venkatraman Gopalan,Alex J Grede,John V Badding,Suzanne E Mohney,Noel C Giebink,Disha Talreja,Alex Molina,Hiu Yan Cheng

doi:10.1063/1.5020814

Xiaoyu Ji, Venkatraman Gopalan + Show 7 more

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https://doi.org/10.1063/1.5020814

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Journal: APL Materials	Publication Date: Apr 1, 2018
Citations: 12	License type: cc-by

Affiliation: Pennsylvania State University

Abstract

Conformally coating textured, high surface area substrates with high quality semiconductors is challenging. Here, we show that a high pressure chemical vapor deposition process can be employed to conformally coat the individual fibers of several types of flexible fabrics (cotton, carbon, steel) with electronically or optoelectronically active materials. The high pressure (∼30 MPa) significantly increases the deposition rate at low temperatures. As a result, it becomes possible to deposit technologically important hydrogenated amorphous silicon (a-Si:H) from silane by a simple and very practical pyrolysis process without the use of plasma, photochemical, hot-wire, or other forms of activation. By confining gas phase reactions in microscale reactors, we show that the formation of undesired particles is inhibited within the microscale spaces between the individual wires in the fabric structures. Such a conformal coating approach enables the direct fabrication of hydrogenated amorphous silicon-based Schottky ...

Highlights

Chemical vapor deposition (CVD) is often used to uniformly coat planar substrate surfaces with technologically relevant materials widely used in microelectronics, optoelectronics, and photovoltaics.[1]
To overcome the kinetic barrier in the pyrolysis reaction of amorphous silicon (a-Si):H, maintain a desirable reaction rate at low enough temperatures and allow for sufficient incorporation of hydrogen; athermal processes such as plasma-enhanced CVD (PECVD),[13] hot wire CVD,[14] and photosensitized CVD15 are used to activate the decomposition of the silane precursor molecules
We demonstrate that a-Si:Hbased Schottky junctions directly made on a flexible stainless steel fabric by this technique function as solar cells

Summary

Introduction

Chemical vapor deposition (CVD) is often used to uniformly coat planar substrate surfaces with technologically relevant materials widely used in microelectronics, optoelectronics, and photovoltaics.[1]. Conformal coating of amorphous silicon and germanium by high pressure chemical vapor deposition for photovoltaic fabrics

Results

Conclusion