METHOD AND SYSTEM FOR TESTING INDIRECT BANDGAP SEMICONDUCTOR DEVICES USING LUMINESCENCE IMAGING

摘要

Embodiments of methods and systems for identifying or determining spatially resolved properties in indirect bandgap semiconductor devices such as solar cells are described. In one embodiment, spatially resolved properties of an indirect bandgap semiconductor device are determined by externally exciting the indirect bandgap semiconductor device to cause the indirect bandgap semiconductor device to emit luminescence (110), capturing images of luminescence emitted from the indirect bandgap semiconductor device in response to the external excitation (120), and determining spatially resolved properties of the indirect bandgap semiconductor device based on a comparison of relative intensities of regions in one or more of the luminescence images (130).

主权项

1. An apparatus for determining spatially resolved properties of an indirect bandgap semiconductor device, said apparatus comprising:
one or more excitation sources configured for exciting said indirect bandgap semiconductor device to emit luminescence; and an image capture device configured for capturing two or more images of said luminescence emitted by said indirect bandgap semiconductor device, wherein the luminescence in each of the two or more luminescence images is emitted from said indirect bandgap semiconductor device in response to different excitation conditions, wherein said one or more excitation sources comprise: a light source configured for illuminating said indirect bandgap semiconductor device with light suitable for inducing photoluminescence in said indirect bandgap semiconductor device; and a voltage varying source configured for applying an electrical signal to contact terminals of said indirect bandgap semiconductor device to induce electroluminescence in said indirect bandgap semiconductor device, or for varying a voltage level across contact terminals of said indirect bandgap semiconductor device relative to an open circuit value.