Voltage tunable electroluminescence of CdTe nanoparticle light-emitting diodes.
Strong electroluminescence was observed in a CdTe nanoparticle light-emitting diode that was fabricated by layer-by-layer assembly of poly(p-phenylenevinylene) and CdTe nanoparticles. The turn-on voltage for the electroluminescence is 4.0 V. The electroluminescence is exclusively from CdTe nanoparticles, with a 30 nm red shift in emission wavelength from the photoluminescence and shifts to longer wavelengths at higher applied voltages. Possible mechanisms for this red shift are discussed, and it is concluded that the de-trapping of surface states and trap centers due to electric excitation, the involvement of traps in the electroluminescence, and the quantum confined Stark effect are the major reasons for the red shift.
Chen
Wei
W
Nomadics, Inc., 1024 South Innovation Way, Stillwater, Oklahoma 74074, USA.
Grouquist
Dennis
D
Roark
Joel
J
D019187:Cadmium Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects; D003460:Crystallization / Q000379:methods; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods*; D004574:Electromagnetic Fields; D049449:Luminescence; D008422:Materials Testing / Q000379:methods; D008854:Microscopy, Electron; D008863:Microspheres; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D010316:Particle Size; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013054:Spectrophotometry, Atomic; D013691:Tellurium / Q000737:chemistry / Q000528:radiation effects
D019187:Cadmium Compounds; D013691:Tellurium; C028337:cadmium telluride