Single-Walled Carbon Nanotube-Germanium Heterojunction for High-Performance Near-Infrared Photodetector

Abstract

In this research, we report on a high-performance near-infrared (near-IR) photodetector based on single-walled carbon nanotube-germanium (SWCNT-Ge) heterojunction by assembling SWCNT films onto n-type Ge substrate with ozone treatment. The ozone doping enhances the conductivity of carbon nanotube films and the formed interfacial oxide layer (GeOx) suppresses the leakage current and carriers’ recombination. The responsivity and detectivity in the near-IR region are estimated to be 362 mA W−1 and 7.22 × 1011 cm Hz1/2 W−1, respectively, which are three times the value of the untreated device. Moreover, a rapid response time of ~11 μs is obtained simultaneously. These results suggest that the simple SWCNT-Ge structure and ozone treatment method might be utilized to fabricate high-performance and low-cost near-IR photodetectors.

Photoresponse of Carbon Nanofiber-Based Photodetector and Its Enhancement on CuNi Nanoparticle Adsorption

“…The smaller BE F value for the CN-CNF sample suggests that its ϕ is larger by 0.6 eV than that of the CNF sample. 58 This ϕ enhancement is in agreement with the report by Qi et al, 19 where the work function of CNTs increases on decorating them with Au NPs. Changes in the work function of a surface are caused essentially by any charge transfer to (or from) an adsorbate, and the associated surface dipole.…”

“…15 The midrange minima (0.1 to 0.3 A/W) in the spectra are also considerably moderate and match well with previous reports. 17,19 The maximum responsivity is higher than the previously reported values for CNT/Si heterojunction photodetectors. 1,15,17 This itself suggests that CNF-based photodetectors have the potential to show a better photoresponse than CNT-based photodetectors.…”

“…As the CN-CNF/Si device has a larger built-in potential and hence a larger electric field across the depletion region, the photogenerated carriers are more quickly swept away on removal of the light, leading to a shorter decay time. 19 There are three key figures of merit of a photodetector: 58,68 (i) the responsivity R, a measure of the sensitivity of the photodetector and given by…”

Challenges and opportunities for SERS in the infrared: materials and methods

“…In turn, technological progress in this area could also benet the telecommunications industry when coupled with the development of highly anisotropic plasmonic materials with resonances in the SWIR. 270,271 Along with the design of SWIRresonant plasmonic materials, we must not forget the development of new resonant and non-resonant SERS reporters for NIR and SWIR applications, which has seen a stall in the recent years. However, developments in the design of NIR uorophores, which are typically also Raman active, can be leveraged to extract useful tips for future revival of this branch of research.…”

Spectral compensation of extended InGaAs photodetector thermal drift in miniaturized FTIR spectral sensors

“…Phototransistors, offering higher gain than photodiodes, are wellsuited for low-light applications. They are often implemented using Si, InGaAs, or HgCdTe materials, providing enhanced sensitivity and amplification capabilities [17][18][19] . Among the various types of NIR photodetectors, semiconductor photodiodes are the most common and versatile.…”