Ultrafast Microwave-hydrothermal Synthesis of CdTe Nanocrystal and Its Application to Fingerprint Detection

We have developed a microwave-assisted hydrothermal method, where both microwave and hydrothermal techniques are utilized to synthesize CdTe nanocrystals with high quality in less than 55 s. Among the known preparation methods, the monodisperse CdTe nanocrystals showing narrow emission spectra, widest scope of emission peak(from 500 nm to 822 nm) and high quantum yield(up to 80%) were synthesized by this route. The quantum yield of CdTe with near-infrared emission(>800 nm) is up to 10%, which is better than that of InAs(0.5%-2%) synthesized in organic phase. Moreover, we detected the latent fingerprints on aluminum, plastic, glass and papers by prepared CdTe nanocrystals, and photoluminescence fingerprints images were taken with a digital camera. Then the images would transmitt into fingerprint detection system of computer to identify the criminals in suit.