Abstract: A high electron mobility transistor (HEMT) includes a substrate comprising indium phosphide and an optional buffer layer immediately adjacent the substrate. A channel layer immediately is adjacent the buffer layer, with the channel layer comprising indium phosphide antimonide and characterized by a formula of InPxSb(1−x), wherein x is about 0.85. The channel layer has a thickness of about 120 Angstroms. A Schottky layer is immediately adjacent the channel layer and a contact layer is immediately adjacent the Schottky layer. The transistor is characterized by a breakdown field of about 400 kV/cm and a saturated velocity of about 8.2×106 cm/s.

Abstract: An optoelectronic device has an epitaxial layer structure that has a substrate and a first layer formed adjacent to the substrate. The first layer may, for example, form a contact layer. A second layer is formed adjacent to the first layer. The second layer forms a selectively optically varying layer, so that during a first state the second layer is optically absorbing and during a second state the layer is optically transparent. A third layer is formed adjacent to the second layer. A fourth layer is formed adjacent to the third layer. The fourth layer is an optically transparent layer. An optoelectronic device and an electronic device may be formed on the same substrate that share the same layers. The layers used depends upon the devices formed.