Te/SnS₂ tunneling heterojunctions as high-performance photodetectors with superior self-powered properties

Abstract

The tunneling heterojunctions made of two-dimensional (2D) materials have been explored to has many intriguing properties like ultrahigh rectification and on/off ratio, superior photoresponsivity and improved photoresponse speed, showing great...

A study on a broadband photodetector based on hybrid 2D copper oxide/reduced graphene oxide

“…First, responsivity demonstrates the capability to convert an optical signal to an electrical signal of a photodetector, which can be presented by eqn (1) : Then, photoconductive gain, which is defined as the number of carriers detected per absorbed photon, can be expressed by eqn (2) : And finally, the ability of a photodetector to detect weak signals of light, known as detectivity, was obtained from eqn (3) : In these equations, I ph stands for the photocurrent, P and A are the light intensity and the effective area of the device (0.7 cm 2 ), h and c represents Planck's constant and light's velocity, and λ and e are the wavelength and the electron charge, in the given order. 43–45 Interestingly, the calculated R and G of our device matched well with the theory: Here, P 0 is the excitation intensity where the surface states are fully filled, T 0 is the carrier life-time at considerably low excitation intensity ( P → 0), T t is the carrier transit time, and n is a phenomenological fitting parameter ( n ≈ 1).…”

“…In these equations, I ph stands for the photocurrent, P and A are the light intensity and the effective area of the device (0.7 cm 2 ), h and c represents Planck's constant and light's velocity, and l and e are the wavelength and the electron charge, in the given order. [43][44][45] Interestingly, the calculated R and G of our device matched well with the theory:…”

Two-Dimensional GeS/SnSe2 Tunneling Photodiode with Bidirectional Photoresponse and High Polarization Sensitivity

“…As V ds increases beyond 0.43 V, the possibility of tunneling is improved, and more and more photogenerated electrons can go through the thinner triangular barrier via the photoinduced FNT process, as shown in Figure e. The difference in the V trans and tunneling barrier widths under dark and light can be attributed to the reduction of the barrier width due to the photodoping effect . Under 635 nm illumination, the photogenerated electron–hole pairs excited in SnSe 2 can be separated through the tunneling process.…”

“…The difference in the V trans and tunneling barrier widths under dark and light can be attributed to the reduction of the barrier width due to the photodoping effect. 41 Under 635 nm illumination, the photogenerated electron−hole pairs excited in SnSe 2 can be separated through the tunneling process. The majority of photogenerated electrons in SnSe 2 can tunnel across the potential barriers and transfer to the GeS side.…”

A Broadband Photodetector Based on Non-Layered MnS/WSe2 Type-I Heterojunctions with Ultrahigh Photoresponsivity and Fast Photoresponse

“…The emergence of 2D non-layered materials with three-dimensional chemically bonded crystal structures not only greatly extends the scope of the inherent layered 2D materials, but also demonstrates a range of interesting properties due to the large number of unsaturated dangling bonds on the surface. These surface active sites make them ideal materials for surface active applications such as catalysts [16], supercapacitors [17], and photodetectors [18,19]. As an important member of the group of non-layered materials, MnS, the group VIIB transition metal chalcogenide, exhibits excellent electronic, photoelectric, and magnetic properties [20,21].…”