Title :
Uniform embedment of CdSe/ZnS quantum dot arrays in thin oxide layers for luminescence down shifting in PV devices
Author :
Sadeghimakki, Bahareh ; Sivoththaman, Siva
Author_Institution :
Centre for Adv. Photovoltaic Devices & Syst. (CAPDS), Waterloo, ON, Canada
Abstract :
A transparent layer consisting of ordered arrays of core/shell cadmium selenide(CdSe)/zinc sulfide(ZnS) quantum dots(QDs) sandwiched in thin silicon dioxide (SiO2) layers has been prepared by embedment of films of QDs in oxide layer deposited by electron beam (e-beam) to use as spectral down shifter. Well ordered nanostructures are revealed by TEM and excitonic photoluminescence (PL) spectra. Low reflection, high transparency and intense PL peaks are the main characteristics of the arrays of QDs introduced into the oxide layer. EQE and IV measurements show that multilayered film of QDs and a near-optimum oxide thickness increase the quantum yield and decrease reflection in the UV-NIR range of the layer, while causing some scattering that tends to reduce the effectiveness of the layer.
Keywords :
II-VI semiconductors; cadmium compounds; electron beams; photoluminescence; photovoltaic cells; semiconductor quantum dots; semiconductor thin films; silicon compounds; solar cells; transmission electron microscopy; wide band gap semiconductors; zinc compounds; CdSe-ZnS; PL spectra; PV devices; SiO2; TEM; UV-NIR; e-beam; electron beam; excitonic photoluminescence spectra; luminescence down shifting; quantum dot arrays; spectral down shifter; thin oxide layers; transparent layer; Carbon; Copper; Optical films; Quantum dots; Silicon; Zinc;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2010 35th IEEE
Conference_Location :
Honolulu, HI
Print_ISBN :
978-1-4244-5890-5
DOI :
10.1109/PVSC.2010.5614495
