Research Repository

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Characterisation and modelling of gallium nitride power semiconductor devices dynamic on-state resistance (2017)
Journal Article
Li, K., Evans, P., & Johnson, M. (2018). Characterisation and modelling of gallium nitride power semiconductor devices dynamic on-state resistance. IEEE Transactions on Power Electronics, 33(6), 5262 - 5273. doi:10.1109/TPEL.2017.2730260

GaN-HEMTs suffer from trapping effects which increases device ON-state resistance (RDS(on)) above its theoretical value. This increase is a function of the applied DC bias when the device is in its OFF state, and the time which the device is biased f... Read More

SiC/GaN power semiconductor devices: a theoretical comparison and experimental evaluation under different switching conditions (2017)
Journal Article
Li, K., Evans, P., & Johnson, M. (in press). SiC/GaN power semiconductor devices: a theoretical comparison and experimental evaluation under different switching conditions. IET Electrical Systems in Transportation, doi:10.1049/iet-est.2017.0022. ISSN 2042-9738

The conduction and switching losses of SiC and GaN power transistors are compared in this paper. Voltage rating of commercial GaN power transistors is less than 650V while that of SiC power transistors is less than 1200V. The paper begins with a theo... Read More

Using multi time-scale electro-thermal simulation approach to evaluate SiC-MOSFET power C=converter in virtual prototyping design tool (2017)
Conference Proceeding
Li, K., Evans, P., & Johnson, C. M. (in press). Using multi time-scale electro-thermal simulation approach to evaluate SiC-MOSFET power C=converter in virtual prototyping design tool

Using virtual prototyping (VP) design tool to eval¬uate power converter electro-thermal performance can help designers to validate prototype in a quick way. However, different system time-scale requires efficient electro-thermal simulation techniques... Read More

SiC/GaN power semiconductor devices theoretical comparison and experimental evaluation (2016)
Conference Proceeding
Li, K., Evans, P., & Johnson, C. M. (2016). SiC/GaN power semiconductor devices theoretical comparison and experimental evaluation

SiC and GaN power transistors conduction loss and switching losses are compared in this paper. In order to compare performance of the same power rating device, a theoretical analysis is given to compare SiC device conduction loss and switching losses... Read More

Damage evolution in Al wire bonds subjected to a junction temperature fluctuation of 30 K (2016)
Journal Article
Agyakwa, P., Yang, L., Arjmand, E., Evans, P., Corfield, M., & Johnson, C. M. (in press). Damage evolution in Al wire bonds subjected to a junction temperature fluctuation of 30 K. Journal of Electronic Materials, doi:10.1007/s11664-016-4519-0. ISSN 0361-5235

Ultrasonically bonded heavy Al wires subjected to a small junction temperature fluctuation under power cycling from 40°C to 70°C were investigated using a non-destructive three-dimensional (3-D) x-ray tomography evaluation approach. The occurrence of... Read More

Design tools for rapid multidomain prototyping of power electronic systems (2015)
Journal Article
Evans, P. L., Castellazzi, A., & Johnson, C. M. (2016). Design tools for rapid multidomain prototyping of power electronic systems. IEEE Transactions on Power Electronics, 31(3), doi:10.1109/TPEL.2015.2437793. ISSN 0885-8993

The need for multidisciplinary virtual prototyping in power electronics has been well established however design tools capable of facilitating a rapid, iterative virtual design process do not exist. A key challenge in developing such tools is identif... Read More

Packaging/assembling technologies for a high performance SiC-based planar power module
Conference Proceeding
Li, J., Agyakwa, P., Evans, P., Johnson, C. M., Zhao, Y., Wu, Y., & Evans, K. (in press). Packaging/assembling technologies for a high performance SiC-based planar power module

This work is to investigate the relevant packaging / assembling technologies for developing a SiC-based planar power module which is aimed to meet the requirements such as operating temperature of -60 °C to 200 °C, SiC devices connected to 540 V DC b... Read More