Abstract: The present invention provides a power control circuit and a dimming control circuit, the circuit includes: a power supply voltage stabilizing circuit, a power adjusting circuit, and an output circuit; the power supply voltage stabilizing circuit is configured to convert a power supply voltage of the voltage source into an input voltage of a preset voltage value, and transmit the input voltage to the power adjusting circuit; the power adjusting circuit is configured to convert the input voltage into an output voltage of a preset power by adjusting a voltage division ratio of the voltage division resistor; the output circuit is configured to operationally amplify and follow the output voltage, and output a brightness control voltage. Using the embodiments of the present invention, power adjustment of the output voltage can be achieved, thereby satisfying the power match for different dimming interfaces.

Abstract: A method for making a heterojunction photovoltaic device (200) is provided for converting solar radiation to photocurrent and photovoltage with improved efficiency. The method and apparatus include an improved window layer (230) having an increased oxygen (140) concentration with higher optical bandgap and photo to dark conductivity ratio. The improved photovoltaic device (200) is made using a deposition method which incorporates the use of a gas mixture of an inert gas (115) and a predetermined amount of oxygen (140), deposited at or near room temperature. Window layers contemplated by the present invention include, but are not limited to, cadmium sulfide (CdS) and various alloys of zinc cadmium sulfide (ZnxCd1-xS). To further increase the efficiency of the resultant photovoltaic device (200), deposition parameters are controlled and monitored to improve the deposited window layer (230).

Abstract: A process for preparing thin Cd2SnO4 films. The process comprises the steps of RF sputter coating a Cd2SnO4 layer onto a first substrate; coating a second substrate with a CdS layer; contacting the Cd2SnO4 layer with the CdS layer in a water- and oxygen-free environment and heating the first and second substrates and the Cd2SnO4 and CdS layers to a temperature sufficient to induce crystallization of the Cd2SnO4 layer into a uniform single-phase spinel-type structure, for a time sufficient to allow full crystallization of the Cd2SnO4 layer at that temperature; cooling the first and second substrates to room temperature; and separating the first and second substrates and layers from each other. The process can be conducted at temperatures less than 600° C., allowing the use of inexpensive soda lime glass substrates.

Abstract: A photovoltaic device has a buffer layer zinc stannate Zn2SnO4 disposed between the semiconductor junction structure and the transparent conducting oxide (TCO) layer to prevent formation of localized junctions with the TCO through a thin window semiconductor layer, to prevent shunting through etched grain boundaries of semiconductors, and to relieve stresses and improve adhesion between these layers.

Abstract: A novel, simplified method for fabricating a thin-film semiconductor heterojunction photovoltaic device includes initial steps of depositing a layer of cadmium stannate and a layer of zinc stannate on a transparent substrate, both by radio frequency sputtering at ambient temperature, followed by the depositing of dissimilar layers of semiconductors such as cadmium sulfide and cadmium telluride, and heat treatment to convert the cadmium stannate to a substantially single-phase material of a spinel crystal structure. Preferably, the cadmium sulfide layer is also deposited by radio frequency sputtering at ambient temperature, and the cadmium telluride layer is deposited by close space sublimation at an elevated temperature effective to convert the amorphous cadmium stannate to the polycrystalline cadmium stannate with single-phase spinel structure.

Abstract: A photovoltaic device having a substrate, a layer of Cd.sub.2 SnO.sub.4 disposed on said substrate as a front contact, a thin film comprising two or more layers of semiconductor materials disposed on said layer of Cd.sub.2 SnO.sub.4, and an electrically conductive film disposed on said thin film of semiconductor materials to form a rear electrical contact to said thin film. The device is formed by RF sputter coating a Cd.sub.2 SnO.sub.4 layer onto a substrate, depositing a thin film of semiconductor materials onto the layer of Cd.sub.2 SnO.sub.4, and depositing an electrically conductive film onto the thin film of semiconductor materials.