Three-Dimensional Dirac Semimetal/Organic Thin Film Heterojunction Photodetector With Fast Response and High Detectivity

Abstract

As a typical three-dimensional Dirac semimetal (3D DSM), Cd3As2 possess ultrahigh carrier mobility, high level of full spectral absorption, fast electron transmission speed, and high photocurrent response, which enable wide applications in infrared photodetector. However, the large dark current of the detector based on Cd3As2 thin film limits the application of the small current response. Hence, we demonstrated heterojunction photodetectors based on n-type 3D DSM Cd3As2 (pristine and Zn doped) and p-type organic (PbPc) by depositing PbPc thin film on Cd3As2 (pristine and Zn doped) thin film using thermal deposition method. These photodetectors can detect the radiation wavelength from 405 to 1,550 nm at room temperature. It is remarkable that this thin film heterojunction photodetector exhibits high detectivity (3.95 × 1011 Jones) and fast response time (160 μs) under bias voltage, which is significantly improved vs. that of Cd3As2-based devices. The excellent performances are attributed to the strong built-in electric field at the interface of p-n junction, which is beneficial for efficient photocarriers collection and transportation. These results show that DSM/organic thin film heterojunction has excellent performance in the application of photodetectors. By combining 3D DSM with organic to form heterojunction, it provides a feasible solution for high-performance photodetectors.

Coexistence of giant Goos–Hänchen shift and high reflectance in Dirac semimetal based multilayered structure

“…26 In contrast, the thickness of the BDS can be tuned, and this allows more freedom in building various micro-and nanostructures via the BDS. 27 These excellent optical properties of the BDS have made it favourable by the research groups in the field of micro-nano optical devices, such as, modulators, 28 photodetectors 29 and filters. 30 Recently, a few studies that investigate GH shifts in structures with BDSs have been carried out.…”

Multiplier Effects of Photodetectors—Source of Gain

“…An optical signal is one of the most important information carriers through space. Researchers have long studied devices (photodetectors) that can detect optical signals [1][2][3][4]. With the advent of the post-Moore era, the trend of the 'Internet of Everything' has led to higher performance and functional requirements for photodetectors [5][6][7].…”

“…How we can further improve the response speed of photomultiplier devices also needs to be further studied. 4.…”