A research team at the University of Wisconsin has created a new phototransistor. It’s the fastest and the most responsive and flexible phototransistor developed to date. According to researcher Zhenqiang “Jack” Ma, this newly created unit showcases both flexibility and high performance, a combination that is not present in any existing phototransistor model.

When it comes to response time and sensitivity, the freshly developed technology outperforms all the previously available flexible phototransistors. The other most prominent feature of this new unit is its versatility. It can be incorporated into a series of devices, from night-vision goggles and digital cameras to instruments used for medical imaging and satellites.

When inserted into a camera, this phototransistor might deliver much clearer and higher definition images, particularly when the camera is used to capture photographs in low-light environments.


For those who don’t know: phototransistors work exactly like eyes of mammals. They collect light and then turn it into an electrical pulse. Such electrical pulses reach the mammals’ brain by means of their nerves. In the case of digital devices, electromagnetic data get transcribed in the form of binary code; this binary code eventually gets converted into an image by means of software.

An innovation that is significantly responsible for making this new phototransistor so efficient is a technique known as “flip-transfer” fabrication. This new technique requires the almost-completed phototransistor to be inverted onto an extremely slim plastic film boasting a metal coating at its bottom. Underneath this ultrathin nano-membrane layer lie the electrodes, which in partnership with the metal coating help in improving light absorption.

Zhenqiang “Jack” Ma, who represents the University of Wisconsin as a professor of computer and electrical engineering, said that this structure has an ultrathin silicon membrane which enables more efficient light absorption as here, the light never gets blocked by a metal layer or layers formed of any other material.

The bottom layer of electrodes and metal eliminate the necessity of having an external amplifier. Ma informed that the unit comes with the ability of sensing weak light. He further added that as a result of being highly flexible, the unit can be used for a variety of purposes. Zhenqiang “Jack” Ma concluded by saying that the new unit might work well in flexible and high-performance photodetection systems.

The study by Wisconsin researchers has been published in the journal Advanced Optical Materials.