My research interests are in the physics and applications of low-dimensional semiconductor nanostructures (quantum wells, wires and dots). I collaborate with many UK and European universities, research institutes and companies.
Two projects are available. (1) Universal memory combines the best features of DRAM and flash, i.e. is non-volatile, low-voltage, non-destructively read, fast, cheap and high endurance. We recently demonstrated novel III-V compound semiconductor candidate universal memory cells (ULTRARAM™), and research is rapidly progressing towards device scaling, fabrication of small arrays and implementation on Si substrates. The objective of this project is to develop and implement the III-V CMOS logic that will enable addressing of bits in large arrays (up to 1 Mbit). It will be suitable for someone with an interest in semiconductor device physics or electronic engineering. (2) VCSELs were recently used for 3D sensing in smartphones. 'Eye-safe’ VCSELs that emit at >1400 nm are preferred, but, all production VCSELs, including those in smartphones, lase at >1000 nm. The project will develop >1400 nm VCSELs, based on our patented GaSb quantum ring technology.
My research interests are in the physics and applications of low-dimensional semiconductor nanostructures (quantum wells, wires and dots), including their study in very high magnetic fields. I collaborate with many UK and European universities, research institutes and companies.
Current research includes the study of quantum dots in different materials systems, with a particular emphasis on 'type-II' GaSb quantum dots and quantum rings embedded in GaAs. These structures confine positive charge (holes) in a very deep potential, but do not confine electrons. This makes them very different from conventional 'type-I' quantum dots that confine both electrons and holes. Besides their unusual physical properties, GaSb quantum dots also have applications in a wide range of areas including solar cells, single-photon LEDs and lasers.
We are also pioneering the development of fast, low-voltage non-volatile memories based on III-V hetereostructures, as a potential candidate 'universal memory' that could be used either as active memory or for data storage.
Other work includes transport properties of two-dimensional electrons in GaSb/AlGaSb heterojunctions and confinement properties of 'conventional' InAs/GaAs quantum dots.
I studied at the University of Southampton and did a PhD and a postdoc at the University of Exeter, before moving to the European mainland. There I briefly worked in Paris, and then at the KU Leuven, Belgium for nearly 10 years, where I investigated semiconductor nanostructures in very high magnetic fields (up to 50 T). I returned to the UK to join the Physics Department in Lancaster in June 2006.
