Team develops photo detectors with quantum efficiency of 100 percent – a major scientific achievement
A recent joint project of Applied Materials Israel and NASA has led to a breakthrough in ultraviolet light photo detectors. In the course of their research, the team developed photo detectors with a quantum efficiency of 100 percent. They did this by adding a layer of boron atoms inside the detectors which made them more efficient.
The subject interests both groups because the new detectors will allow NASA to carry out astronomical research in space with higher levels of accuracy and to develop more precise telescopes, and they’ll help Applied Materials improve the efficiency of metrology systems that measure the production processes of semiconductors.
Hysteresis is no laughing matter
The head of the Israeli research team, Shraga Tsur, said the joint research project had focused on finding a solution to two substantial problems that characterize ultraviolet light sensors: the existence of a hysteresis curve and too short a life span for the sensors. An hysteresis curve occurs when the sensor does not return to its initial condition after exposure, which causes errors in the image it produces. The hysteresis problem makes it impossible to carry out repeatable measurements because every exposure leaves an imprint on the sensor, a kind of shadow of the previous image produced.
The short life span is manifested by the fact that today’s sensors, especially the shorter frequency ones, are destroyed after 1-4 billion exposures to laser light, which means that they have to be replaced every 6-24 months. The purpose of the research was to develop a sensor that lasts for more than ten billion pulses and can be used for more than five years on a production line.
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H/t: IVC Research Center (in Hebrew)