Applications of Cadmium Telluride (CdTe) in Nanotechnology

Abstract

Cadmium telluride quantum dots (CdTe QDs) were prepared by chemical reaction and used to fabricate electroluminescence quantum dot hybrid junction device. QD-LED was fabricated using TPD: PMMA/CdTe/Alq 3 device which synthesized by phase segregation method. The hybrid white light-emitting devices consist of three layers deposited successively on the ITO glass substrate; the first layer was of tetra-phenyl diaminobiphenyl (TPD) polymer mixed with polymethyl methacry-late (PMMA) polymers, while the second layer was 0.5 wt% of the (CdTe) QDs for hybrid device, whereas the third layer was tris (8-hydroxyquinoline) aluminum (Alq 3). The organic light-emitting device (OLED) was considered by room temperature photoluminescence (PL) and electroluminescence (EL). Current-voltage (I-V) characteristics indicate that the output current is good compared to the few voltage (6 V) used which gives good results to generate white light. The electrolu-minescence (EL) spectrum of hybrid device shows a wide emission band covering the range 350-700 nm. The emissions causing this white luminescence were identified depending on the chromaticity coordinates (CIE 1931): x = 0.32, y = 0.33. The correlated color temperature (CCT) was found to be about 5886 K. Fabrication of EL devices from semiconductor material (CdTe QDs) between two layers, organic polymer (TPD) and organic molecules (Alq 3), was effective in white light generation. The recombination processes and I-V characteristics give rise to the output current which is good compared to the few voltages used which give good results to generate light.