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Zhores Alferov, born in 1930, Russian physicist who was cowinner of the 2000 Nobel Prize in physics. Alferov shared half of the Nobel Prize with American physicist Herbert Kroemer for their independent yet parallel improvements to semiconductors during the early 1960s. Their enhanced semiconductor design is widely used in microelectronics. The other half of the Nobel Prize in physics was awarded to a scientist whose invention helped launched the ongoing revolution in information and communication technology: American electrical engineer and inventor Jack S. Kilby. In 1958 Kilby designed and constructed the first integrated circuit.

Zhores Ivanovich Alferov was born in 1930 in Vitebek, Belarus, in what was then part of the Union of Soviet Socialist Republics (USSR). After graduating in 1952 from the V. I. Ulyanov Electrotechnical Institute in Saint Petersburg (now known as the Saint Petersburg State Technical University), he joined the staff of the A. F. Ioffe Physico-Technical Institute, also located in Saint Petersburg. Alferov earned his doctoral degree in physics and mathematics at the institute in 1970, and he became the institute’s director in 1987.

In the early 1960s Alferov’s work centered on creating faster transistors. Transistors regulate the passage of electrons and are found in almost all electronic devices. Semiconductors, materials that have the properties of both a conductor (capacity to carry an electric current) and an insulator (resistance to an electric current), are one of the key components of transistors. Conventional semiconducting materials, such as silicon, face a limitation: negatively charged electrons flow in one direction, leaving positively charged “holes” that flow in the opposite direction. These opposing flows reduce the transistor’s efficiency.

Alferov tried a new method: Instead of working with a single block of semiconducting material, he experimented with structures made of layers of different semiconducting materials. By combining separate materials such as gallium arsenide and aluminum gallium arsenide in layers as thin as a few atoms, he vastly improved transistor performance. These layered semiconductors are called heterostructures.

Alferov also realized that under the right circumstance, electrons and holes could be combined and used to generate light. This was the concept behind the heterostructure laser, which Alferov and Kroemer proposed independently in 1963. Alferov’s team was later among the first to construct practical lasers based on semiconductor heterostructures.

Today, the heterostructures that Alferov and Kroemer pioneered are used in satellite communication systems, in the base stations for mobile-telephone networks, and in the fiber-optic technology that speeds Internet data throughout the world. Heterostructure lasers make it possible for CD players to reproduce music and for the bar-code scanners in stores to automatically record sales. Future improvements in laser-diode technology may one day replace the conventional light bulb with light-emitting devices based on semiconductor heterostructures.