Study On Colloidal Pbse Quantum Dots Phosphors And Light Emitting Diodes In Near Infrared

Near-infrared colloidal quantum dots have many excellent properties,like their flurescence spectrum was located in the infrared range and has a widely tunable range.Their emission peak also narrowly,and possess high quantum efficiency.Meanwhile,the core-shell quantum dots can improve the tocicity of quantum dots and improve their stability under the condition of ensuring these advantages.Therefore,both colloidal quantum dots or core-shell quantum dots in the biology,optoelectronic devices,light-emiiting devices,gas detection and other fields have a very broad application prospects.In order to solve the high cost produced by the traditional near-infrared light source,the complex processing technology,the unadjust wavelength,the poor stability and uneasy relased toxicity.In this paper,two novel near-infrared light sources were fabricated by GaN-based blue-light-emitting diodes using solid-state PbSe/CdSe/ZnSe core-shell quantum dots and liquid colloidal PbSe quantum dots as light conversion materials.And we use of three different sizes of liquid colloidal PbSe dots to produce multi-wavelength liquid near-infrared quantum dot light source,the details are as follows:1.Fabrication and characterization of a near infrared light emitting diode based on PbSe/CdSe/ZnSe core/shell quantum dots.The existing near-infrared quantum dot light source,whether it is a photoluminescet device or an electroluminescent device,is much lighter in luminous efficiency than a quantum light emitting device with visible light.In this paper,PbSe/CdSe/ZnSe core/shell quantum dots are dispersed in UV glue as light conversion material,and a novel solid-state near-infrared light source is fabricated by GaN blue light emitting diode as the excitation light source.The device has good stability and non-toxic green environmental protection and so on.2.Fabrication and characterization of a near infrared light emitting diode based on liquid PbSe quantum dots.As the solid-stated quantum dendritic films make the surface of the colloid quantum dots very seriousdefects,which exacerbates the exciton in the process of Auger recombination,resulting in its luminous efficiency has been low.Therefore,the liquid PbSe quantum dots are injected into the quartz glass hemisphere and then combined with GaN light emitting device.Then a new type of liquid strcture near infrared light source was fabricated.Through the characterization of the performance of the light source,it is found that the optimal external quantum efficiencny of the device can reach 5.30%.While the device has good stability;we can change the wavelength of light just by changing the size of quantum dot.3.Utilizing three sizes of PbSe quantum dots light emitting to fabricating multi wavelength near-infrared light emitting diode.The colloidal PbSe quantum dots solution of 2.51,4.64 and 6.03 nm was mixed into a quartz glss and then combined with GaN blue light.We obtained a near infrared quantum dot light source with three emission bands.