With general lighting applications being responsible for over 20% of the energy consumption in the United States, advances in solid-state lighting have the potential for considerable energy and cost savings. The United States Department of Energy predicts that the increased use of solid state lighting will result in a 46% lighting consumption energy savings by the year 2030. Smart lighting systems have the potential for reducing energy costs while also providing a means for short distance data transmission via free space optics. The group III-nitride (III-N) family of materials, including aluminum nitride (AlN), gallium nitride (GaN), indium nitride (InN), their binary and ternary alloys, are uniquely situated to provide light emitting diodes (LEDs) across the full visible spectrum, photodetectors (PDs) and high power, high speed transistors. In this work, aluminum gallium nitride (AlGaN) / GaN high electron mobility transistors (HEMTs) and indium gallium nitride (InGaN) photodiodes (PDs) are fabricated and characterized. HEMTs and LEDs (or PDs) are grown on the same substrate for the purpose of creating electronic and optoelectronic integrated circuits.