Keeping small electrical gadgets cool using quantum wells

Researchers from the University of Tokyo have been able to develop a new process for electrical cooling without needing any moving parts. When a sufficient amount of voltage is applied to quantum wells made from semiconductor aluminum gallium arsenide, heat can be shed from electrons in a process called “evaporative cooling.” Devices that are based on this principle can be added to circuit boards by using conventional methods of semiconductor fabrication for helping smartphones and laptops to avoid performance issues that are caused by high temperatures.

Consumers love devices that they can carry with themselves. But as these gadgets are getting smaller in size and more advanced, the concern for overheating further increases. The fans that are currently available for cooling are noisy, bulky and their parts can fail. Now, researchers at the Institute of Industrial Science at the University of Tokyo have announced a new, solid-state solution that is made from semiconductors and can easily be directed into smart phones and laptops.

Quantum wells are basically very small structures that are able to trap electrons. The type of quantum well that was used in this research is known as an asymmetric double-barrier heterostructure. In smart phones and laptops, and other digital gadgets of small size, layers of aluminum gallium arsenide separate the very narrow gallium arsenide wells. When the bias voltage that applied equals the energy of the quantum level present inside the well, electrons are able to use the resonant tunneling for easily passing through a barrier. However, the electrons that possess high kinetic energies only will have the ability to continue through a second barrier. As the hotter and fast-moving electrons escape, and the cooler and slow-moving ones are trapped, the device gets colder.