Journal Article

Unity quantum yield of photogenerated charges and band-like transport in quantum-dot solids

van Huis, Marijn A., van der Zant, Herre S. J., Houtepen, Arjan J., Savenije, T. J., Aerts, Michiel, Siebbeles, Laurens D. A., Schins, Juleon M., Talgorn, Elise, Gao, Yunan, Kunneman, Lucas T.

2011

Overview

Solid films of colloidal quantum dots show promise in the manufacture of photodetectors and solar cells. These devices require high yields of photogenerated charges and high carrier mobilities, which are difficult to achieve in quantum-dot films owing to a strong electron–hole interaction and quantum confinement. Here, we show that the quantum yield of photogenerated charges in strongly coupled PbSe quantum-dot films is unity over a large temperature range. At high photoexcitation density, a transition takes place from hopping between localized states to band-like transport. These strongly coupled quantum-dot films have electrical properties that approach those of crystalline bulk semiconductors, while retaining the size tunability and cheap processing properties of colloidal quantum dots. Thin films of strongly coupled PbSe quantum dots exhibit light-induced charge generation with a yield of one electron and one hole per photon over a wide temperature range.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 639/925/357/1017 / 639/925/357/551 / 639/925/357/995 / Chemistry and Materials Science / Colloids - chemistry / Electrical properties / Electron Transport / Electrons / Lead - chemistry / Ligands / Materials Science / Microscopy, Electron, Scanning / Nanoparticles - chemistry / Nanostructures - chemistry / Nanotechnology / Nanotechnology - instrumentation / Nanotechnology and Microengineering / Photons / Quantum Dots / Quantum Theory / Selenium Compounds - chemistry / Semiconductors / Solar cells / Spectrum analysis / Temperature / Terahertz Spectroscopy - methods