Electronics pioneer Born January 20, 1921; Died February 21, 2008. Professor Walter Spear, who has died aged 87, was one of the most outstanding experimentalists of his age. His ground-breaking work on amorphous semiconductors laid the foundation for much of today's multibillion-dollar solar-panel industry.

Spear was born in Germany and came to Britain just before the war. He studied at Birkbeck College, University of London, where his practical skills and love for experimentation emerged. While at Birkbeck, he developed and built, with Werner Ehrenberg, a microfocus X-ray generator that helped lead to the discovery of the double-helix structure of DNA.

Spear then joined the academic staff at the University of Leicester, where he spent 14 years, and where he met Peter LeComber, who became his collaborator. The two joined the staff of the University of Dundee in 1969, Spear as Harris Professor of Physics, and established the Amorphous Materials Research Group in a disused textile store.

Spear was famed for saving money by building complex circuits in tobacco tins to provide electrical screening, and for recycling brass components for vacuum chambers from one experiment to another.

His early work in electronic transport in solids was widely recognised and led to his election as Fellow of the Royal Society.

At a time when there was an emerging interest in flat-film silicon amorphous semiconductors, many of the underlying theories in this area were developed by Nobel prizewinner Sir Nevill Mott, and he and Spears developed a long-term friendship.

Theoretical predictions by Mott suggested that the "doping" process, on which depends the technology behind electronics' main substance, silicon, would not be possible in the amorphous state.

However, in a landmark paper by Spear and LeComber in 1975, it was demonstrated that it was indeed possible to create dramatic changes in conductivity.

This started a revolution in the field of amorphous semiconductor research by making inexpensive silicon-based thin film electronic devices possible, and companies and groups across the world started studying the material.

Spear and LeComber, working as one of the most remarkable and durable partnerships in the history of experimental physics, were generally a step ahead, and produced a number of world firsts. They made the first amorphous silicon p-n junction, the building block of electronic devices, and showed that it had photovoltaic (PV) properties - ie, could convert light into electricity.

These properties were soon realised in the form of thin film solar cells by researchers in the RCA laboratories in the US. In the period immediately following the seminal 1975 paper, attention focused on improving the performance of the first PV devices.

In the widely held belief that oil reserves might soon be exhausted, many major oil companies began investing in this area of research, before new fields were discovered.

This caused no problem for the Dundee Group as the world was to be stunned by another world first when the amorphous silicon thin film transistor was announced.

This was followed by a demonstration of its use in the active matrix liquid crystal display made jointly at the Royal Signals and Radar Establishment in Malvern.

This device is found in virtually every notebook display and every mobile phone screen and is the basis for the market in flat-panel displays.

Spear was also a gifted teacher and conveyed his enthusiasm for his subject at all levels, from undergraduate to international conferences. There was always a buzz of excitement at conferences when he would start to present his latest paper, and they would always lead to spirited debate.

He started postgraduate education in this area, attracting students from all over the world to the Dundee laboratories. Many of his students went on to form important research groups across Europe and the United states. It is a measure of his modesty that he was always more proud of his students and their successes than his many awards.

He was particularly pleased when Peter LeComber was elected to the Royal Society and devastated when, soon after, in 1992, he died suddenly at an early age. This event unquestionably hastened Spear's complete withdrawal from the field of active research at that time.

Such a distinguished career led to many international prizes, including the European Physical Society Europhysics Prize in 1976; the Max Born Medal and Prize for Physics in 1977; the Rank Prize in Optoelectronics in 1988; and the Royal Society Rumford Medal in 1990. In 1988 he delivered the Bakerian Lecture to the Royal Society.

When not immersed in his work, Spear had a keen interest in European culture. He was a very accomplished cello player, and in his retirement could be found playing in chamber groups around Dundee.

His work and influence will be long remembered by those fortunate enough to have worked or studied in the Dundee laboratories. His legacy, held, as so much, jointly with his close friend and colleague LeComber, is the ubiquitous liquid crystal display of the mobile information age.

Spear is survived by his wife Hilda, two daughters, Gillian and Katherine, and two grandchildren. Mervyn Rose