Facile Fabrication of PbS Nanocrystal:C₆₀ Fullerite Broadband Photodetectors with High Detectivity

Abstract

Hybrid PbS nanocrystal/C 60 fullerite photodetectors are fabricated using a simple one-step drop casting procedure onto pre-patterned interdigitated electrodes. The devices exhibit a broad spectral response from the near UV through to the near infrared yielding a detectivity, D * , of above 10 10 Jones from 400 nm to ≈ 1050 nm. The ability to further extend the spectral response to wavelengths ≈ 1350 nm in the near infrared via tuning of the PbS nanocrystal diameter is also demonstrated. The dynamic responses of the devices are presented, exhibiting a fast photocurrent rise time ( < 40 ns) followed by a long bi-exponential decay with characteristic lifetimes of τ 1 = 5.3 μ s ± 0.1 μ s and τ 2 = 37.8 μ s ± 0.7 μ s. These devices, which have a detectivity approaching that of commercial detectors, a broader spectral response, and a fast rise time, offer an attractive low-cost solution for large-area broadband photodetectors.

Ultrahigh Performance C60 Nanorod Large Area Flexible Photoconductor Devices via Ultralow Organic and Inorganic Photodoping

“…It should be noted that the photodoped devices we report here work on a fundamentally different mechanism as compared to more commonly reported planar heterojunction donor/acceptor (D/A) devices reported previously2930313233. In typical blend devices the relative donor to acceptor volume ratio is very high and the devices rely primarily on the absorption and conductivity of the donor material.…”

Lead sulphide nanocrystal photodetector technologies

“…Hybrid inorganic-organic photoconductors based on type-II heterojunctions via blending PbS NCs with widely used fullerene acceptors, PCBM and C60 crystals have also been reported. 48,49 One advantage of hybrid devices is that they can operate even with oleic acid ligands as the photoexcited charge transport occurs through acceptor materials, although long ligands may supress the electron transfer process from PbS NCs to the acceptor material. In such hybrid devices both charge carriers may be collected depending upon the charge percolation pathways in the blend film and also the type of NC ligand used.…”

The room temperature phosphine-free synthesis of near-infrared emitting HgSe quantum dots

“…3 In recent years Esmaeili-Zare et al used a sonochemical technique to synthesis HgSe nanocrystals with a reported band edge of 2.23 eV. 13 The report described the use of SeCl 4 and HgCl 2 in the presence of hydrazine and capping agents, where ultrasonic waves were used to irradiate the reaction to form the required nano-crystals.…”