Low light level solar cell

Claim 2

In a photovoltaic cell of the type having a first current collecting film, an amorphous silicon film having a p-i-n structure and having the p-region in contact with the first current collecting film, and a second current collecting film in contact with the n-region of said amorphous silicon film, the improvement comprising use of a doped microcrystalline silicon film having a thickness greater than 500 angstroms in place of at least one of said p-region and said first current collecting film or said n-region and said second current collecting film.

Claim 3

A photovoltaic device comprising, a transparent front-face electrode, a thin film photovoltaic amorphous silicon layer on said front face electrode, a back-face electrode consisting of a layer of microcrystalline silicon having a thickness greater than 500 angstroms directly contacting said amorphous silicon layer.

Claim 4

A photovoltaic device comprising, a transparent front-face electrode, a thin film photovoltaic amorphous silicon layer on said front face electrode, a back-face electrode consisting of a layer of microcrystalline silicon having a thickness greater than 500 angstroms directly contacting said amorphous silicon layer.

Claim 5

A photovoltaic device according to claim 2 wherein said microcrystalline layer is highly doped.

Claim 6

A photovoltaic device according to claim 2 wherein said back-face electrode is a least 1000 angstroms thick.

Claim 7

A photovoltaic device according to claim 2 wherein said amorphous silicon layer comprises a p-doped region in direct contact with said front face electrode and an intrinsic region in direct contact with said back-face electrode and wherein said microcrystalline layer is n-doped.

Claim 8

A photovoltaic device according to claim 2 wherein said amorphous silicon layer comprises a p-doped region in direct contact with said front fact electrode, an intrinsic region, and an n-doped region in direct contact with said back-face electrode and wherein said microcrystalline layer is n-doped.

Claim 9

In a process for manufacturing a photovoltaic device of the type wherein a thin film silicon photovoltaic structure is deposited by glow discharge in silane onto a transparent conductive substrate, said substrate forming a front-face current collecting film, and a back-face current collecting film is deposited onto said thin film silicon structure, the improvement comprising; depositing said back-face current collecting film in the form of microcrystalline silicon having a thickness greater than 500 angstroms by glow discharge in silane without removing said substrate from the glow discharge chamber after deposition of said thin film silicon photovoltaic structure.

Claim 10

In a process for manufacturing a photovoltaic device of the type wherein a thin film silicon photovoltaic structure is deposited by glow discharge in silane onto a transparent conductive substrate, said substrate forming a front-face current collecting film, and a back-face current collecting film is deposited onto said thin film silicon structure, the improvement comprising; depositing said back-face current collecting film in the form of microcrystalline silicon having a thickness greater than 500 angstroms by glow discharge in silane without removing said substrate from the glow discharge chamber after deposition of said thin film silicon photovoltaic structure.