Ridley has conducted work on negative differential resistance (NDR), instabilities and hot-electron transport in semiconductors. In the early 1960s,[4] he jointly discovered the electron transfer mechanism (Ridley–Watkins–Hilsum effect) which underlies microwave generation in Gunn diodes, and he was the first to discover the impurity barrier mechanism for NDR, and to demonstrate its existence in germanium. He was also the first to describe the consequences of NDR instabilities in terms of propagating dipole domains and current filaments. The existence of these nonlinear entities has been verified in a wide variety of solids. His work on acoustoelectric instabilities led to his invention of the microsonic analogue of the laser. He has made original contributions to the theory of electron transitions in solids, particularly impurity scattering and multiphonon processes. This work is the subject of his monograph Quantum Processes in Semiconductors, widely used as a reference text.[5][6]
He wrote three popular books, Time, Space and Things (1976), which has been translated into multiple languages, The Physical Environment (1979) and On Science (2001).[1][6][7]
^ abc"Brian Ridley". London: Royal Society. One or more of the preceding sentences may incorporate text from the royalsociety.org website where "all text published under the heading 'Biography' on Fellow profile pages is available under Creative Commons Attribution 4.0 International License." "Royal Society Terms, conditions and policies". Archived from the original on 10 July 2017. Retrieved 16 December 2017.{{cite web}}: CS1 maint: bot: original URL status unknown (link)