Memory phototransistors based on exponential-association photoelectric conversion law.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30894530.
- Also identified by DOI 10.1038/s41467-019-09206-w and PMC identifier 6426936.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Ultraweak light detectors have wide-ranging important applications such as astronomical observation, remote sensing, laser ranging, and night vision. Current commercial ultraweak light detectors are commonly based on a photomultiplier tube or an avalanche photodiode, and they are incompatible with microelectronic devices for digital imaging applications, because of their high operating voltage and bulky size. Herein, we develop a memory phototransistor for ultraweak light detection, by exploiting the charge-storage accumulative effect in CdS nanoribbon. The memory phototransistors break the power law of traditional photodetectors and follow a time-dependent exponential-association photoelectric conversion law. Significantly, the memory phototransistors exhibit ultrahigh responsivity of 3.8 × 10<sup>9</sup> A W<sup>-1</sup> and detectivity of 7.7 × 10<sup>22</sup> Jones. As a result, the memory phototransistors are able to detect ultraweak light of 6 nW cm<sup>-2</sup> with an extremely high sensitivity of 4 × 10<sup>7</sup>. The proposed memory phototransistors offer a design concept for ultraweak light sensing devices.