Quantifying electric fields in semiconductor devices. The schematic shows electric field distribution in the channel of a GaN transistor; laser beams highlight the second harmonic generation (SHG) nature of the technique. (Image: Yuke Cao)

Researchers have developed a technique that will allow for faster communication systems and better energy-saving electronics. The breakthrough was made by establishing how to remotely measure the electric field inside a semiconductor device for the first time.

Semiconductor device design can be trial and error, though more commonly it is based on a device simulation that then provides the basis for the manufacture of the semiconductor devices for real-life applications. When these are new and emerging semiconductor materials, it has often been unknown how accurate and correct these simulations are.

Semiconductors can be made to conduct positive or negative charges and can therefore be designed to modulate and manipulate current. However, these semiconductor devices do not stop with silicon — there are many others including Gallium Nitride. These semiconductor devices, which can convert an AC current from a power line into a DC current, result in a loss of energy as waste heat.

A voltage is applied to an electronic device and as a result, there is an output current used in the application. Inside the electronic device is an electric field that determines how the device works and how long it will be operational. To make good performance and long-lasting electronic devices out of these new materials, it is important that researchers find the optimal design where electric fields do not exceed the critical value, which would result in their degradation or failure.

Experts plan to use newly emerging materials such as gallium nitride and gallium oxide rather than silicon, allowing operation at higher frequency and at higher voltages, respectively, so that new circuits are possible that reduce energy loss. This work provides an optical tool to enable the direct measurement of electric field within these new devices. This will underpin future efficient power electronics in applications such as solar or wind turbine stations, electric cars, trains, and planes.

Since these devices are operated at higher voltages, this means electric fields in the devices are higher, which in turn means they can fail easier. The new technique enables researchers to quantify electric fields within the devices, allowing accurate calibration of the device simulations that design the electronic devices so the electric fields do not exceed critical limits and fail.

For more information, contact Professor Martin H. H. Kuball at This email address is being protected from spambots. You need JavaScript enabled to view it..