Control of Back Surface Reflectance from Aluminum Alloyed Contacts on Silicon Solar Cells

doi:10.1109/PVSC.1996.564053

Control of Back Surface Reflectance from Aluminum Alloyed Contacts on Silicon Solar Cells

NREL

Research output: Contribution to conference › Paper

Abstract

A process for forming highly reflective aluminum back contacts with low contact resistance to silicon solar cells is described. By controlling the process conditions, it is possible to vary the silicon/aluminum interface from a specular to a diffuse reflector while maintaining a high interface reflectance. The specular interface is found to be a uniform silicon/aluminum alloy layer a fewangstroms thick that has expitaxially regrown on the silicon. The diffuse interface consists of randomly distributed (111) pyramids produced by crystallographic out-diffusion of the bulk silicon. The light trapping ability of the diffuse contact is found to be close to the theoretical limit. Both types of contacts are found to have specific contact resistivities of 10/sup -5/ ..Omega.. -cm/sup2/. The process for forming the contacts involves illuminating the devices with tungsten halogen lamps. The process is rapid (under 100 s) and low temperature (peak temperature < 580 deg. C), making it favorable for commercial solar cell fabrication.

Original language	American English
Pages	501-503
Number of pages	3
DOIs	https://doi.org/10.1109/PVSC.1996.564053
State	Published - 1996
Event	Twenty Fifth IEEE Photovoltaic Specialists Conference - Washington, D.C. Duration: 13 May 1996 → 17 May 1996

Conference

Conference	Twenty Fifth IEEE Photovoltaic Specialists Conference
City	Washington, D.C.
Period	13/05/96 → 17/05/96

NLR Publication Number

NREL/CP-22386

Access to Document

10.1109/PVSC.1996.564053

Cite this

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title = "Control of Back Surface Reflectance from Aluminum Alloyed Contacts on Silicon Solar Cells",

abstract = "A process for forming highly reflective aluminum back contacts with low contact resistance to silicon solar cells is described. By controlling the process conditions, it is possible to vary the silicon/aluminum interface from a specular to a diffuse reflector while maintaining a high interface reflectance. The specular interface is found to be a uniform silicon/aluminum alloy layer a fewangstroms thick that has expitaxially regrown on the silicon. The diffuse interface consists of randomly distributed (111) pyramids produced by crystallographic out-diffusion of the bulk silicon. The light trapping ability of the diffuse contact is found to be close to the theoretical limit. Both types of contacts are found to have specific contact resistivities of 10/sup -5/ ..Omega.. -cm/sup2/. The process for forming the contacts involves illuminating the devices with tungsten halogen lamps. The process is rapid (under 100 s) and low temperature (peak temperature < 580 deg. C), making it favorable for commercial solar cell fabrication.",

author = "NREL",

year = "1996",

doi = "10.1109/PVSC.1996.564053",

language = "American English",

pages = "501--503",

note = "Twenty Fifth IEEE Photovoltaic Specialists Conference ; Conference date: 13-05-1996 Through 17-05-1996",

}

TY - CONF

T1 - Control of Back Surface Reflectance from Aluminum Alloyed Contacts on Silicon Solar Cells

AU - NREL, null

PY - 1996

Y1 - 1996

N2 - A process for forming highly reflective aluminum back contacts with low contact resistance to silicon solar cells is described. By controlling the process conditions, it is possible to vary the silicon/aluminum interface from a specular to a diffuse reflector while maintaining a high interface reflectance. The specular interface is found to be a uniform silicon/aluminum alloy layer a fewangstroms thick that has expitaxially regrown on the silicon. The diffuse interface consists of randomly distributed (111) pyramids produced by crystallographic out-diffusion of the bulk silicon. The light trapping ability of the diffuse contact is found to be close to the theoretical limit. Both types of contacts are found to have specific contact resistivities of 10/sup -5/ ..Omega.. -cm/sup2/. The process for forming the contacts involves illuminating the devices with tungsten halogen lamps. The process is rapid (under 100 s) and low temperature (peak temperature < 580 deg. C), making it favorable for commercial solar cell fabrication.

AB - A process for forming highly reflective aluminum back contacts with low contact resistance to silicon solar cells is described. By controlling the process conditions, it is possible to vary the silicon/aluminum interface from a specular to a diffuse reflector while maintaining a high interface reflectance. The specular interface is found to be a uniform silicon/aluminum alloy layer a fewangstroms thick that has expitaxially regrown on the silicon. The diffuse interface consists of randomly distributed (111) pyramids produced by crystallographic out-diffusion of the bulk silicon. The light trapping ability of the diffuse contact is found to be close to the theoretical limit. Both types of contacts are found to have specific contact resistivities of 10/sup -5/ ..Omega.. -cm/sup2/. The process for forming the contacts involves illuminating the devices with tungsten halogen lamps. The process is rapid (under 100 s) and low temperature (peak temperature < 580 deg. C), making it favorable for commercial solar cell fabrication.

U2 - 10.1109/PVSC.1996.564053

DO - 10.1109/PVSC.1996.564053

M3 - Paper

SP - 501

EP - 503

T2 - Twenty Fifth IEEE Photovoltaic Specialists Conference

Y2 - 13 May 1996 through 17 May 1996

ER -

Control of Back Surface Reflectance from Aluminum Alloyed Contacts on Silicon Solar Cells

Abstract

Conference

NLR Publication Number

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Cite this