Abstract: A nanocrystalline superlattice solar cell utilizing a superlattice constructed from alternating amorphous and nanocrystalline layers is provided. The amorphous layers of the superlattice include Germanium. In one embodiment the Germanium content is homogeneous across the amorphous layer. Alternatively, the Germanium content is graded across the amorphous layer from a lower content to a greater content as the amorphous layer is grown. The grading of Germanium content can vary from 0% or greater at a boundary with the preceding layer to 100% or less at a boundary with a subsequent layer. The grading may be continuous or may occur in discreet step increases in Germanium content.

Abstract: Integrated photoluminescence (PL)-based chemical and biological sensors are provided comprising a photodetector (PD), a long-pass filter, an excitation source, and a sensing element, all based on thin films or structures. In one embodiment the light source is an organic light emitting device (OLED) and the sensing element is based on thin films or solutions in microfluidic channels or wells. The PD and optical filters are based on thin film amorphous or nanocrystalline silicon and related materials. In another embodiment, sensor components are fabricated on transparent substrates, which are attached back-to-back to generate a compact, integrated structure.

Abstract: Method of counteracting the effects of undesired contaminants in an amorphous semiconductor, and the resulting semiconductor product. An overcompensating agent is incorporated in the semiconductor in a restricted or limited region which is less than the entirety of the semiconductor body. The semiconductor is desirably of amorphous silicon. The undesired contaminant is a p acceptor and the compensating dopant is an n donor. Alternatively, the undesired contaminant can be an n donor and the compensating dopant can be a p acceptor. Typical p acceptors are residual boron and typical n donors are phosphorous. The compensation takes place over the range from about 1 to about 25% of the maximum thickness of the region of compensation. The compensating dopant is present in a limited amount ranging from about 1 part to about 50 parts per million.

Abstract: The specification discloses a P-I-N device wherein a double heterojunction is provided by a body of intrinsic amorphous silicon sandwiched between two microcrystalline silicon layers.

Abstract: Method of producing amorphous semiconductor hydrides (hydrogenated amorphous semiconductors) with specified bandgaps. The desired bandgap is achieved by controlling the temperature and partial pressure of higher order semiconductanes which are created pyrolytically, for example, on a substrate using a hot-wall epitaxial reactor.

Abstract: Preparation of amorphous semiconductor carbides that are suitable for use in a wide variety of devices by the pyrolytic decomposition of a mixture of one or more semiconductanes and one or more carbanes.

Abstract: A photovoltaic cell having a zinc phosphide absorber. The zinc phosphide can be a single or multiple crystal slice or a thin polycrystalline film. The cell can be a Schottky barrier, heterojunction or homojunction device. Methods for synthesizing and crystallizing zinc phosphide are disclosed as well as a method for forming thin films.

Abstract: Method of producing amorphous semiconductor hydrides (hydrogenated amorphous semiconductors) with specified bandgaps. The desired bandgap is achieved by controlling the temperature and partial pressure of higher order semiconductanes which are created pyrolytically, for example, on a substrate.

Abstract: A photovoltaic stack comprising at least two p.sup.+ i n.sup.+ cells in optical series, said cells separated by a transparent ohmic contact layer(s), provides a long optical path for the absorption of photons while preserving the advantageous field-enhanced minority carrier collection arrangement characteristic of p.sup.+ i n.sup.+ cells.

Abstract: A photovoltaic device includes at least two solar cells made from Group IV elements or their alloys in the amorphous state mounted on a substrate. The outermost or first cell has a larger bandgap than the second cell. Various techniques are utilized to improve the efficiency of the device.

Abstract: A multiple gap photovoltaic device having a transparent electrical contact adjacent a first cell which in turn is adjacent a second cell on an opaque electrical contact, includes utilizing an amorphous semiconductor as the first cell and a crystalline semiconductor as the second cell.

Abstract: A solar cell comprising a back electrical contact, amorphous silicon semiconductor base and junction layers and a top electrical contact includes in its manufacture the step of heat treating the physical junction between the base layer and junction layer to diffuse the dopant species at the physical junction into the base layer.