LED array unit with silicon microreflector

A light emitting diode (LED) array unit for a light source of isolated power transmission or a display panel was fabricated using LED chips which were mounted on a silicon microreflector. The reflector was formed on a (100) silicon wafer by means of anisotropic chemical etching. An isolated power supply which consisted of an infrared LED array unit and single silicon crystal solar cells was developed. Maximum conversion efficiency of 2.3% was achieved. The silicon microreflector kept the conversion efficiency nearly constant independent of the input power to the LEDs and improved the light directive characteristics. The fabricated isolated power supply has low capacitive leakage current and negligible small internal noise. A small, high resolution LED display panel can also be realized using a LED array unit with silicon microreflector. The LED display panel has superior characteristics such as long lifetime, high brightness and wide visual angle compared with plasma and liquid crystal displays