Metal halide perovskites- An Overview

Metal halide perovskites come with several benefits that include the likes of high light absorption coefficient, high charge mobility among others. These factors have made metal halide perovskites a useful feature for solar cell fabrication. 

Researchers at two Netherlands universities, namely, the Dutch Organization for Applied Scientific Research and the Eindhoven University of Technology have utilised a photodetector derived from metal halide perovskite used to fabricate a thin scanner.  A published paper, titled Nature Electronics, stated this scanner that can be put to use for fingerprints and paper documents. 

Silicon has been found as an excellent alternative for its ability to sense light and other kinds of radiation as well, called photodetectors, which at its core, are integral to several sensors.  Albert J.J.M van Breeman and his colleagues researched and journaled their findings in the paper, which stated that the integration of fabricating photodetectors with minimal dark currents into high-intensity backplanes was still a tall order. 

The team used a layer of Cs0.18FA0.82Pb (I0.82Br0.18)3, having caesium (Cs+) and formamidinium (CH (NH2)2 +, FA) cations to fabricate the photodetector. With this, the group also used a silicon nitride edge cover layer that was 50 nanometres thick between the electrode and the PTAA that helped cut the electrode current leakage and subsequently blacken current density. 

In the end, the researchers kept a 100-nanometre thick indium tin oxide electrode, transparent in nature, on top of a thin-film encapsulation barrier. This succeeded in an inverted stack design that contained molybdenum-chrome alloy at the bottom. The integration. with a thin-film transistor array resulted in the creation of a near-complete scanner. A sensor as highly sensitive as this may have numerous applications, the most prominent one being helping prevent spoof attacks.  

Attackers can find out any important information on their own devices, replicating them with the help of synthesized copies of their biometric data. The study gave findings that in future when perovskite image sensors are integrated correctly, it could help enhance biometric identification tools.