Electrical resistance mapping of quantum well materials

Quantum wells are a versatile and important class of materials with a wide range of potential applications. However, there are a number of challenges associated with using quantum wells. NPL's Microwave Resonator system can be used to mitigate against some of these challenges, and it is helping to accelerate the development of quantum well based devices. 

Quantum wells are a thin layer of semiconductor material sandwiched between two layers of wider bandgap material. The width of the quantum well is typically on the order of a few nanometers, which is small enough that quantum effects become important. 

Quantum wells are of interest to people working in a variety of sectors, including electronics, optoelectronics, and quantum computing. They are used in a variety of optoelectronic devices, including lasers, light-emitting diodes (LEDs), and solar cells. They are also being investigated for use in other applications, such as thermoelectrics and quantum computing. 

Challenges of using quantum wells 

There are a number of challenges associated with using quantum wells. These include: 

• Fabrication challenges: Quantum wells are typically fabricated using semiconductor manufacturing techniques, which can be complex and expensive. The width of the quantum well must be precisely controlled, and the interfaces between the quantum well and the surrounding materials must be very smooth. 
• Defects: Quantum wells are susceptible to defects, which can disrupt the quantum confinement of the electrons and holes. These defects can be introduced during the fabrication process, or they can occur over time due to exposure to environmental factors. 
• Heat dissipation: Quantum well devices can generate a lot of heat, which can limit their performance. Heat dissipation is a major challenge for the development of quantum well based lasers and solar cells. 
• Compatibility with existing technologies: Quantum well devices must be compatible with existing technologies in order to be widely adopted. This means that they must be compatible with standard semiconductor manufacturing processes, and they must be able to interface with existing electronic devices. 

NPL's Microwave Resonator system 

NPL's Microwave Resonator system can be used to take measurements that help orgnaisations mitigate against some of the challenges of using quantum wells. The Microwave Resonator system uses a patented non-contact method to map wafers of quantum well materials to show areas of high and low electrical resistance. This information can be used to identify areas of the wafer that are more likely to be defective, and it can also be used to optimize the fabrication process. 

Are you interested in learning more about our quantum capabilities?

Contact a member of NPL's quantum team today to schedule a consultation. We can discuss your specific needs and how our quantum technologies can help you achieve your goals.

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