Dr Robert Hoye
Fellow in Materials Science
Royal Academy of Engineering Research Fellow

Kim and Juliana Silverman Research Fellow

BE(Hons) in Chemical and Materials Engineering (The University of Auckland, New Zealand)

PhD in Materials Science (University of Cambridge)

photovoltaics; semiconductors; light-emitting diodes; defects; charge-carrier recombination

Dr. Robert Hoye’s main interests are in (1) the discovery of defect-tolerant semiconductors for optoelectronics, and (2) techniques for the scalable synthesis of high-quality functional materials.

Defect-tolerant semiconductors offer the opportunity to achieve high performance when synthesised by low-cost, low-temperature methods. This is particularly important for technologies that currently rely on high-purity inorganic materials synthesised by expensive techniques, such as photovoltaics and solid-state lighting. Materials that are defect-tolerant are characterised by shallow defect levels in the bandgap, high dielectric constants and low effective masses. This results in the defects being more benign, which relaxes constraints in how carefully the material needs to be synthesised. Lead-halide perovskites are a family of defect-tolerant semiconductors that have been very successful in optoelectronics. Synthesised by cheap solution-processing, long diffusion lengths (> 1 μm) and high photoluminescence quantum efficiencies (>80%) have been achieved and reproduced by many groups around the world. This has resulted in rapid increases in the efficiencies of photovoltaics and light emitting diodes (LEDs) after only a few years development. Dr. Hoye has developed new oxide electrodes to pair lead-halide perovskite with silicon to create efficient and stable tandem solar cells, as well as to achieve ultrasharp emission, which has important implications for ultrahigh definition displays. However, a key part of his research into defect-tolerant semiconductors is to find lead-free alternatives to the perovskites, achieving recent success with several bismuth-based compounds, such as bismuth oxyiodide.

Realising low-cost optoelectronics commercially requires high-throughput synthesis methods. On this topic, Dr. Hoye is developing new oxide materials using atmospheric pressure chemical vapour deposition (AP-CVD). This is a technique he worked on during his PhD. He has shown that AP-CVD grows thin films an order of magnitude faster than conventional atomic layer deposition, but at lower temperatures than chemical vapour deposition. He has shown it possible to finely tune the properties of several metal oxides (such as ZnO, TiO2 and SnO2) to achieve highly-performing solar cells and LEDs, as well as achieve films that are conformal to high-aspect ratio nanostructures.

Lecturer for Part III Materials Science (Semiconducting Materials Characterisation). Lent term 2018. Michaelmas term 2018 and 2019.

Lecturer for Part IB Materials Science (Course E: Materials Chemistry). Lent term 2019

Undergraduate supervisions: Part IB Materials Science

Worked with the Royal Academy of Engineering to develop a resource to enrich the STEM curriculum with real-world Materials Engineering examples. Theme: Engineering Materials for a Greener Planet.  

Cambridge Science Festival

2019: IOM3 ’15 under 30’

2019: Forbes ’30 under 30’ - Europe. Category: Science & Healthcare

2019: Elected a Professional Member of the Institute of Materials, Minerals and Mining (IOM3)

2018: Young Engineer of the Year, awarded by the Royal Academy of Engineering

2016-2019: Junior Research Fellowship at Magdalene College, Cambridge

2016: Work on bismuth-based solar cells recognised as one of 12 ’Science Highlights’ of 2016, out of all 605 groups funded by the US Department of Energy

2015: Toby Jackman Prize for the most outstanding PhD thesis, awarded by St. Edmund’s College, Cambridge

2014: American Alumni Award by St. Edmund’s College, Cambridge

2014: Associate Studentship, awarded by the Nano Science & Technology Doctoral Training Centre

2012-2014: Cambridge-Rutherford Memorial Scholarship to fully-fund PhD at the University of Cambridge. Awarded by the Royal Society of New Zealand and the Cambridge Trusts

2011: James Gordon Goodfellow Memorial Prize for the most distinguished academic performance for the entire Bachelor of Engineering (Hons) degree programme

Full list available on Google Scholar.

Robert L. Z. Hoye, et al., Identifying and Reducing Interfacial Losses to Enhance Color-Pure Electroluminescence in Blue-Emitting Perovskite Nanoplatelet Light-Emitting Diodes. ACS Energy Letters, 2019, 4, 1181-1188

Robert L. Z. Hoye, et al., Strongly Enhanced Photovoltaic Performance and Defect Physics of Air-Stable Bismuth Oxyiodide. Advanced Materials, 2017, 29, 1702176

* Press release: https://www.cam.ac.uk/research/news/non-toxic-alternative-for-next-gener...

Robert L. Z. Hoye, et al., Perovskite-Inspired Photovoltaic Materials: Toward Best Practices in Materials Characterisation and Calculations. Chemistry of Materials, 2017, 29, 1964-1988

* Highlighted by the American Chemical Society and listed as an example of best research by Chemistry of Materials.

Robert L. Z. Hoye, et al., Enhanced Performance in Fluorene-Free Organometal Halide Perovskite Light-Emitting Diodes using Tunable, Low Electron Affinity Oxide Electron Injectors, Advanced Materials, 2015, 27, 1414-1419

* Cited over 100 times and included in the top 1% of Materials Science articles by citations for 2015-2019 by Web of Science

Robert L. Z. Hoye, et al., Improved Open-Circuit Voltage in ZnO-PbSe Quantum Dot Solar Cells by Understanding and Reducing Losses Arising from the ZnO Conducting Band Tail. Advanced Energy Materials, 2014, 4, 1301544