Won the 2000 Nobel Prize in Physics "for basic work on information and communication technology.” Kroemer won half the prize jointly with Zhores I. Alferov, "for developing semiconductor heterostructures used in high-speed- and opto- electronics.” They shared the prize with Jack S. Kilby who won "for his part in the invention of the integrated circuit." Kroemer and Alferov independently formulated a laser using a semiconducting material and a double heterostructure. A double heterostructure is composed of two different semiconducting materials, with one surround by the other. The two different materials have different allowed energy levels. The boundaries between different layers play a very important role. This material was made into a continuous wave laser, and is used in many electronic devices. It is used in optoelectronic devices that convert an electric signal to light and vice versa.