Semiconductor Physics, Quantum Electronics & Optoelectronics. 2005. V. 8, N 3. P. 054-059.
Photovoltaic and optical properties of a polymer-PbS nanocomposite
1Institute of Physics, NAS of Ukraine, 46, prospect Nauky, 03028 Kyiv, Ukraine
Abstract. Photovoltaic and optical properties of a polymer-PbS nanoparticles in
polyvinyl alcohol (PVA) films and the effect of annealing in air at various temperatures
on these properties are studied in this work. In the range of 1.0 to 3.7 eV, absorption
spectra of PbS nanocomposite films are correctly fitted by five Gaussian bands peaking
at 1.5, 1.84, 2.41, 3.06, and 3.58 eV. A characteristic feature of the films is the presence
of green and blue luminescence with intensity maxima at 2.25 and 3.02 eV, respectively.
The luminescence intensity strongly depends on the excitation energy and the annealing
temperature in air. The highest intensity of the green luminescence is observed under the
excitation with 2.35 eV radiation, whereas the intensity of the blue luminescence peaks
under 3.46 eV excitation. After annealing at 370 K, the intensity of the green
luminescence decreases a few times whereas the intensity of the blue emission increases.
The photovoltaic sensitivity of the PbS nanocomposite films depends on the annealing
conditions, attaining the maximum after annealing in air at approximately glass transition
temperature of PVA (370 K). The spectral range of the photosensitivity of PbS
nanocomposite films is wider than that of CdSe- and CuInS2-polymer nanocomposite
films.
Keywords: PbS nanocomposite, absorption spectra, luminescence, photovoltage.
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