A Practical Porous Silicon Device Structure for Increased Electroluminescent Efficiency

This work reports on the results of two innovative designs for efficient silicon-based light emitting devices(LEDs). The two devices demonstrated improvement on the extraction efficiency of photons produced by electroluminescent porous silicon. With the previous structures, the produced luminescence was collected from the surface of the devices through the uses a redesigned top contact along with an etch into the active region of the device. The second type used an edge emitting arrangement. The new surface emitting device showed visible luminescence that was easily seen in a dim ambient. the edge emitting structure exhibited an increase in intensity of between two and three orders of magnitude. This paper will not discuss the physical device structures and the strategies by which the emitted photons are extracted