Postsynthesis Crystallinity Improvement of Colloidal CdTe Nanoparticles Using Rapid Thermal Annealing

Abstract

Rapid thermal annealing has been applied to poly(acrylic acid)-capped CdTe nanoparticles. This annealing process has shown to provide some control over the semiconductor core properties, while preserving the capping ligand intact. The photoluminescence and absorption properties of the nanoparticles remain nominally unchanged up to annealing temperatures of 400 °C and annealing durations of 30 s. This process was found to be an effective postsynthesis means of improving the crystallinity of the semiconductor core. The crystallinity enhancement is identified by solution-based Raman spectroscopy using a hollow-core photonic crystal fiber. This novel method of detecting a crystalline change in nanoparticles is corroborated by powder X-ray diffraction measurements and X-ray photoelectron spectroscopy.

Synthesis of quantum dot doped chalcogenide glasses via sol-gel processing

“…26). 19 In either case, these results indicate that ZnS provides an environment that is suitable for post-deposition annealing under nitrogen gas. 8(a).…”

Conductivity enhancement of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) films post-spincasting

“…As such, significant effort has been aimed at enhancing semiconductor polymer carrier mobility through the optimization of their structural and molecular order. 8 One of the techniques that has been previously exploited to improve these properties is thermal annealing in ovens. It has been demonstrated that the crystalline morphology and the orientation of spin cast conjugated polymers films could be modestly improved through oven thermal annealing or melt crystallization approaches.…”

“…9 Also, improvement to the crystalline morphology of water soluble CdTe polymer encapsulated quantum dots was achieved using the same annealing technique. 8 RTA is an attractive process, as it offers a route to control and manipulate thin film properties after casting on the substrate beyond what is achievable using conventional oven-based annealing. 10 In this study, we examine the influence of the RTA annealing temperature on the optical and morphological properties of PEDOT:PSS film.…”

Examining metal nanoparticle surface chemistry using hollow-core, photonic-crystal, fiber-assisted SERS

“…The waveguide characteristics and the accessibility to the hollow cladding channels of HCPCF have opened up many possibilities for chemical and biochemical sensing utilizing fluorescence [8], Raman scattering [9][10][11][12], and SERS [13][14][15]. The utilization of HCPCF can result in the enhancement of the Raman signal strength by approximately 2 orders of magnitude [16].…”

“…We have examined the root causes of the signal enhancement in previous studies [10,12,16]. The enhancement in the detected Raman signal is due to the increased interaction length and efficient collection of the Raman scattering signal via the bandgap effect over this extended interaction length.…”