Abstract
Preparation of PbTe–ZnTe nanocomposite thin film is investigated by one-step synthesis using hot-wall deposition with multiple solid-state resources of PbTe and ZnTe. X-ray diffraction and Raman spectrum indicate that composite thin films contain PbTe with NaCl structure, and ZnTe with zinc-blende structure. High-resolution transmission electron microscopy and fast Fourier transform analysis indicate that isolated PbTe nanocrystalline facets are dispersed in ZnTe matrix. The two compounds phase-separate at hetero-interface without forming a ternary solid solution Zn1−x Pb x Te. Therefore, simultaneous evaporation of the multiple resources provides a phase-separating nanocomposite with faceted PbTe nanocrystals embedded in ZnTe matrix. The PbTe crystallizes even at a relatively low substrate temperature of 274 K.
Highlights
A combination of lead and zinc chalcogenide system is valuable for preparing a nanocomposite thin film due to the reasons as follows: (1) this system phase-separates in thermal equilibrium without forming a solid solution, (2) band-gap difference between lead and zinc chalcogenide is relatively large, capable of exhibiting quantum confinement effects, and (3) vapor pressures of lead and zinc chalcogenide are similar and relatively large, capable of simultaneously thermal-evaporating the solid-state substances
To retain the most important characteristic of phase separation between lead and zinc chalcogenide, a technique of hot-wall deposition (HWD) should be employed due to a state near thermal equilibrium in a deposition atmosphere [10]. Based on these material designs, we proposed a composite thin film with PbSe nanocrystals embedded in a ZnSe matrix by one-step synthesis using HWD with multiple evaporation sources of PbSe and ZnSe [11]
Simultaneous evaporation of solid-state sources (PbTe and ZnTe) is available for preparing a nanocomposite thin film with PbTe nanocrystals embedded in ZnTe matrix using HWD
Summary
Nanoscale semiconductor embedded in a wide-gap material has potential application for quantum dot solar cells due to tunableness for absorbing effective energy region in solar radiation spectrum and impact ionization for producing multiple electron–hole pairs per photon [1]. To retain the most important characteristic of phase separation between lead and zinc chalcogenide, a technique of hot-wall deposition (HWD) should be employed due to a state near thermal equilibrium in a deposition atmosphere [10] Based on these material designs, we proposed a composite thin film with PbSe nanocrystals embedded in a ZnSe matrix by one-step synthesis using HWD with multiple evaporation sources of PbSe and ZnSe [11]. Different evaporation sources (PbSe or PbTe), provide similar nanocrystalline PbSe, but the XRD peaks of pure PbSe nanocrystals are weak even at a relatively high substrate temperature of 403 K [13], whereas nanoscale PbSe:Te crystallizes even at 274 K [12] These results suggest that slight inclusion of Te in PbSe nanocrystal
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
