Transparent solar cell and method of fabrication

DETAILED DESCRIPTION The present invention provides improved devices such as transparent solar cells and optical filters.
It also provides improved methods for forming those devices.
In contrast with devices and methods previously disclosed by the present inventor, these improved devices and methods use fewer layers resulting in simpler, less expensive fabrication processes and resulting in simpler devices along with other beneficial results.
Moreover, compared with other fabrication techniques, the present invention allows for the fabrication of devices that are transparent using existing fabrication equipment and processing steps, while allowing those processes to be done quickly.
In some embodiments, the processes may be completed on low melting point substrates that would be destroyed using previously known techniques.
In a first embodiment of the present invention, a method is provided for fabricating a device.
The method comprises forming a first conductive layer overlying a substrate, forming a first amorphous silicon layer overlying the first conductive layer and annealing the first amorphous silicon layer by applying thermal energy with a laser to convert amorphous silicon of the first amorphous silicon layer into polycrystalline silicon.
A second conductive layer may be formed overlying the polycrystalline silicon.
The methodology produces a Schottky barrier diode between the conductive layer and the polycrystalline silicon.
The resulting device may be used as a solar cell or as an optical filter.
Steps of the methodology may be repeated to create successive layers of conductors and polycrystalline silicon.
In another embodiment of the present invention, a method is provided for fabricating a transparent device.
The method comprises forming a first conductive layer overlying a transparent substrate, forming a first amorphous silicon layer overlying the first conductive layer; and converting the first amorphous silicon layer into polycrystalline silicon by application of thermal energy while maintaining the transparent substrate at a temperature of less than 450