Abstract
Semiconductor nanocrystals or quantum dots were proposed as tunable lumophores for a wide range of applications in the late 1990s: including biolabelling, single photon emitters, tunable LEDs and solar cells. However challenges in synthesizing these materials have led to only slow success in the development of devices.
In this talk the speaker will present results demonstrating that, with careful optimization, p-n junctions can be fabricated from nanocrystal inks using solution processing. Annealing converts the inks into continuous semiconductor films with well-defined optical and electrical properties. Unlike the case for PbS(Se) based PV devices, quantum size effects are not beneficial for tuning the film band gap of CdTe PV systems. The goal of the solution processing is to convert the small crystals into a bulk semiconductor film.
The main advantages of nanocrystal inks in this case are: 1) solution processing is scalable and avoids expensive vacuum processing steps; 2) the annealing can be carried out at low temperatures, which enable deposition onto polymer and other soft surfaces for flexible electronics. The speaker will show how devices with efficiencies up to 10% may be fabricated at a fraction of the cost of conventional PV devices. He will discuss the advantages and disadvantages of this approach.
About the speaker
Prof Paul Mulvaney received his PhD in Physical Chemistry from the University of Melbourne in 1989. He was research scientist at the Hahn Meitner Institute for Nuclear Research from 1989 to 1992. He returned to the University of Melbourne as an ARC QEII Research Fellow in 1993, and became a faculty in 1997. He is currently ARC Laureate Professor and Professor of Chemistry.
Prof Mulvaney’s research interests include energy transfer in nanoscale systems, surface forces and self-assembly, nanomechanics, surface plasmon spectroscopy and solar energy conversion. His current research work focuses on plasmonics – the optical properties of small metal crystals. The goal of this research is to use spectroscopy to follow the basic steps in catalysis, which are essential to understanding processes such as water splitting, artificial photosynthesis and pollutant removal. He has published about 250 scientific papers and these have accumulated an average of 80 citations per scientific paper. He is co-inventor on 5 commercialized patents. He is an associate editor of the journal ACS Nano and on the editorial advisory board of 4 other journals.
Prof Mulvaney is a Fellow of the Royal Australian Chemical Institute and the Australian Academy of Science.
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