High efficiency solar cells based on indium nitride heterostructures

As a class of materials, the binary and ternary Group III-nitrides are ideally suited for the next generation of high efficiency inorganic photovoltaic (PV) solar cells. These materials can be described as ionic semiconductors with a relatively wide spread of band-gaps ranging from 6.2 eV for AlN, to 3.4 eV for GaN, and 0.65 eV for InN, and means that both the ternary alloys, InGaN and InAlN can have band-gaps spanning the entire visible range of the EM spectrum. Hence they are ideal materials for photon collection at different energies within a solar cells that can potentially be implemented using conventional multi-junction architecture, or via novel PV design (e.g. such as an intermediate band solar cell), or by incorporating a systematically graded alloy composition that absorbs all energies across the structure. Such designs have been predicted to have overall device efficiencies approaching 70% and hence there is considerable interest in these materials. Other potential advantages include the long life-time (relative to organic materials) and the resistance of these materials to radiation damage, making them ideal for applications in space.

A complete range of surface and interface science techniques will be used to investigate the structure, interface chemistry and near-surface electronic excitations (phonons and plasmons) in III-nitride heterostructures and probe the electronic structure of several shallow buried interfaces. These results will be compared with data from more conventional electrical characterisation techniques (e.g. Hall, C-V profiling, PL etc.) and data from fabricated PV device structures. There is also a strong collaboration with Ritsumeikan University (Japan), University of Madrid (Spain), the Universities of Liverpool and Nottingham, and with EPSRC’s III-V Central Facility at the University of Cambridge, who will supply the materials for these studies.

The project would be suitable for candidates with excellent degrees in Physics, Chemistry or Electrical Engineering who have a strong interest in semiconductor physics or surface and interface science. Candidates must be able to work in an interdisciplinary team and communicate effectively outside their field. A willingness to travel, work at national facilities and develop new collaborations would also be advantageous.

Further detailed information can be obtained from Prof Chris McConville ([Email Address Removed])