Jr. Heine et al., Synthesis of CdSe quantum dot ZnS matrix thin films via electrospray organometallic chemical vapor deposition, J CRYST GR, 195(1-4), 1998, pp. 564-568
A modified organometallic chemical vapor deposition technique is used to in
corporate luminescing II-VI nanocrystals (NCs) into ZnS thin films. The NCs
are synthesized in organic solution and consist of a CdSe core and ZnS she
ll. The ZnS matrix is deposited by OMCVD from diethyl zinc and hydrogen sul
fide while the NCs are delivered to the film surface via electrospray. Vary
ing the size of the CdSe NC core enables tunable emission from the blue to
the red. The ZnS shell provides electronic and chemical passivation of the
CdSe core improving its luminescence and thermal stability. The thin films
exhibit room temperature photoluminescence (PL) and cathodoluminescence (CL
) dominated by emission from the NCs. PL quantum efficiencies greater than
10% have been achieved. The dependence of thin film luminescence and micros
tructure on deposition temperature is studied using optical photoluminescen
ce and X-ray diffraction. Particular emphasis is placed on the relationship
between the host ZnS structure and the optical properties of the NC-ZnS co
mposite thin film. (C) 1998 Elsevier Science B.V. All rights reserved.