In another flask, a Te source solution was formed by dissolving 0.5 mmol of Te powder in 3 mL tri-n-octylphosphine TOP. The Cd stock solution was heated to 260°C, and then the Te solution was quickly injected. The reaction proceeded for 3 to 4 min at 260°C to Captisol manufacturer produce CdTe nanocrystals with a tetrapod shape. As to CdSe QDs, similar recipe and procedure were used just by replacing Te with 1.0 mmol of Se powder. Both CdTe NTs and CdSe QDs were purified with chlorobenzene/ethanol solvent/antisolvent for at
least four times. The final products were dissolved separately in chlorobenzene to form a 40-mg/mL solution. Fabrication of solar cells with CdTe/CdSe hybrid bulk heterojunction The hybrid bulk heterojunction solar cells with a structure of ITO/CdTe/CdTe: CdSe/ZnO/Al was fabricated as follows: firstly, all
patterned conductive indium tin oxide (ITO)/glass substrate were ultrasonically cleaned by soap RXDX-101 mouse and water, deionized water, acetone, and isopropanol for 15 min, respectively, and then dried at 110°C for 1 h in air. The active layer was produced by spin coating a 30-nm CdTe NTs layer firstly and then seven layers of CdTe/CdSe hybrid. The weight-to-weight ratio of CdTe NTs to CdSe QDs was controlled in the range RG7420 clinical trial of 6:1 to 1:2. Following each spin coating, the substrates were heat-treated at 150°C in air (sample A) or solvent treatment using 3-mercaptopropionic acid (MPA)/methanol solution (10% by volume) (sample B). For solvent treatment, two drops of MPA/methanol solution were dispensed Tau-protein kinase onto the CdTe layer or CdTe/CdSe hybrid layer, and the substrate was spun at 2,500 rpm for 15 s after a 6-s wait. Three rinse steps with methanol were applied under the same operation. Afterward, the substrates were annealed at 150°C for 10 min. Finally, a
ZnO buffer layer of about 20 nm is formed on the surface of the substrate by spin coating a ZnO quantum dot solution in isopropanol, as was usually done [12]. The solar cell fabrication was finished by thermally depositing a 100-nm aluminum cathode on top. Characterization The shape of CdTe NTs and CdSe QDs was characterized by transmission electron microscopy (TEM) on a Hitachi H-800 (Hitachi High-Tech, Tokyo, Japan) at an acceleration voltage of 80 kV. HBH thin film surface and cross-sectional morphology were measured by field emission scanning electron microscopy (JEOL 7006 F, JEOL Ltd., Tokyo, Japan). Atomic force microscopy (AFM) test was carried out on a Solver P47 SPM (NT-MDT, Moscow, Russia) under semi-contact mode. The crystal structure of hybrid was researched by Raman scattering on a Renishaw RW1000 (Renishaw, Wotton-under-Edge, UK) confocal microscope with a 514-nm line of Ar+ iron laser as exciting light. Absorption measurements were carried out on Varian Cary-5000 model (Agilent Technologies, Inc., Santa Clara, CA, USA) UV-visible infrared spectrophotometer. Electrochemical impedance spectra were recorded on a CHI 660E (CH Instruments, Austin, TX, USA) electrochemical workstation.