초록 ▼

One or more thin film solar cells in which the intrinsic layer of substantially amorphous semiconductor alloy material thereof includes at least a first band gap portion and a narrower band gap portion. The band gap of the intrinsic layer is spatially graded through a portion of the bulk thickness,

One or more thin film solar cells in which the intrinsic layer of substantially amorphous semiconductor alloy material thereof includes at least a first band gap portion and a narrower band gap portion. The band gap of the intrinsic layer is spatially graded through a portion of the bulk thickness, said graded portion including a reg

대표청구항 ▼

A solar cell including at least one layer of thin film substantially amorphous intrinsic semiconductor alloy material; said intrinsic layer characterized by at least a first portion of the thickness thereof having a bandgap and a second portion of the thickness thereof having a second bandgap narrow

A solar cell including at least one layer of thin film substantially amorphous intrinsic semiconductor alloy material; said intrinsic layer characterized by at least a first portion of the thickness thereof having a bandgap and a second portion of the thickness thereof having a second bandgap narrower than the first bandgap portion; said intrinsic layer sandwiched between oppositely doped layers of semiconductor alloy material; the bandgap of all portions of the intrinsic layer not contiguous to the intrinsic layer-dopant layer interfaces being less than the bandgap of the dopant layers; the improvement comprising, in combination: at least one band gap modifying element introduced into at least a substantial portion of the bulk thickness of the intrinsic layer so as to spatially grade the bandgap of said intrinsic layer over a substantial portion of the bulk thickness thereof, said graded portion including a region removed from the intrinsic layer-dopant layer interfaces. A solar cell as in claim 3, wherein the percentage of germanium incorporated into said silicon germanium alloy is graded through a substantial portion of the bulk thickness of the intrinsic layer. A solar cell as in claim 4, further including at least one additional solar cell disposed in optical and electrical series relation to said one solar cell so as to form a tandem photovoltaic structure.