Activating Carrier Multiplication in PbSe Quantum Dot Solids by Infilling with Atomic Layer Deposition.
نویسندگان
چکیده
Carrier multiplication-the generation of multiple electron-hole pairs by a single photon-is currently of great interest for the development of highly efficient photovoltaics. We study the effects of infilling PbSe quantum-dot solids with metal oxides by atomic layer deposition on carrier multiplication. Using time-resolved microwave conductivity measurements, we find, for the first time, that carrier multiplication occurs in 1,2-ethanedithiol-linked PbSe quantum-dot solids infilled with Al2O3 or Al2O3/ZnO, while it is negligible or absent in noninfilled films. The carrier-multiplication efficiency of the infilled quantum-dot solids is close to that of solution-dispersed PbSe quantum dots, and not significantly limited by Auger recombination.
منابع مشابه
Phonons Do Not Assist Carrier Multiplication in PbSe Quantum Dot Solids
Carrier multiplication (CM)the Coulomb scattering whereby a sufficiently energetic charge excites a valence electronis of interest for highly efficient quantum dot (QD) photovoltaics. Using time-resolved microwave conductivity experiments on 1,2ethanedithiol-linked PbSe QD solids infilled with Al2O3 or Al2O3/ZnO by atomic layer deposition, we find that CM and hot-carrier cooling are temperatu...
متن کاملPbSe quantum dot field-effect transistors with air-stable electron mobilities above 7 cm2 V(-1) s(-1).
PbSe quantum dot (QD) field effect transistors (FETs) with air-stable electron mobilities above 7 cm(2) V(-1) s(-1) are made by infilling sulfide-capped QD films with amorphous alumina using low-temperature atomic layer deposition (ALD). This high mobility is achieved by combining strong electronic coupling (from the ultrasmall sulfide ligands) with passivation of surface states by the ALD coat...
متن کاملRobust, functional nanocrystal solids by infilling with atomic layer deposition.
Thin films of colloidal semiconductor nanocrystals (NCs) are inherently metatstable materials prone to oxidative and photothermal degradation driven by their large surface-to-volume ratios and high surface energies. (1) The fabrication of practical electronic devices based on NC solids hinges on preventing oxidation, surface diffusion, ripening, sintering, and other unwanted physicochemical cha...
متن کاملThe Effect of pH on the Optical Band Gap of PbSe Thin Film with Usability in the Quantum Dot Solar Cell and Photocatalytic Activity
This study was an attempt to provide a simple solution processed synthesis route for Lead Selenide (PbSe) nanostructure thin films using the chemical bath deposition (CBD) method which is commercially available in inexpensive precursors. In the CBD method, the preparation parameters play a considerable role and determine the nature of the final product formed. Known as two main factors, the eff...
متن کاملThe photothermal stability of PbS quantum dot solids.
We combine optical absorption spectroscopy, ex situ transmission electron microscopy (TEM) imaging, and variable-temperature measurements to study the effect of ultraviolet (UV) light and heat treatments on ethanedithiol-treated PbS quantum dot (QD) films as a function of ambient atmosphere, temperature, and QD size. Film aging occurs mainly by oxidation or ripening and sintering depending on Q...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The journal of physical chemistry letters
دوره 4 11 شماره
صفحات -
تاریخ انتشار 2013