“UNAM researchers demonstrate near-unity emitting copper-doped colloidal semiconductor quantum wells for luminescent solar concentrators”. Since the first demonstration of the colloidal quantum dots (CQDs), doping has been widely investigated in the quantum confined semiconductors. In colloidal nanocrystals, doping enables the means for tailoring the electronic structure and optical properties in addition to size, shape and composition tuning. Recently, luminescent solar concentrators (LSCs) based on doped CQDs have aroused attention as a low-cost alternative for solar energy utilization. Effective use of these doped CQDs in LSCs requires a number of important properties including high photoluminescence (PL) quantum efficiency (QE), tunable solar absorption, and good photostability. Apart from these fundamental necessities for the LSC emitter, it is essential to avoid the suffering of the captured photons in the waveguide from various scattering and reabsorption losses.
In a recent communication published in Advanced Materials, a team of researchers led by Prof. Hilmi Volkan Demir from Bilkent University have successfully demonstrated the first account of doping into colloidal quantum wells. According to Prof. Demir, the Cu-doped CdSe quantum wells (CQWs) in principle can overcome the above-mentioned limitations in the LSCs with their strong quantum confinement in 1D owing to their magic sized vertical thicknesses. In addition to Stokes-shifted and tunable dopant-induced photoluminescence emission, the copper doping into CQWs enables them with near-unity quantum efficiencies (up to ~97%), substantially high absorption cross-section and inherently step-like absorption profile. Furthermore, by using both experimental analysis and numerical modeling these doped CQWs are shown to be excellent candidates for LSCs. Prof. Demir emphasized that the present work provides a solid platform for applying doping concepts in 2D colloidal quantum wells, which can be extended into different dopant/core and new 2D architectures for future solar light harvesting applications.
Further details can be found in the latest communication in Advanced Materials (DOI: 10.1002/adma.201700821, http://onlinelibrary.wiley.com/doi/10.1002/adma.201700821/full). More information on related research activities may be obtained from the Demir Research group webpage (http://web2.bilkent.edu.tr/ds/ ).
Prof. Hilmi Volkan Demir
Dr. Manoj Sharma
Kıvanç Güngör, PhD Student
Dr. Murat Olutaş
Yusuf Keleştemur, PhD Student