Light harvesting in hybrid epitaxial/colloidal nanostructures

The performance of light harvesting devices is improved by utilising resonance energy transfer. A hybrid structure of colloidal quantum dots (QDs) and a quantum well (QW) p-i-n heterostructure is investigated. After highly absorbing QDs absorb photons, the excitations are efficiently transferred to a QW p-i-n heterostructure via resonance energy transfer. The generated electron-hole pairs in the heterostructure are subsequently separated by the built-in electric field and collected by the corresponding electrodes. In order to increase the energy transfer rate, the donor-acceptor separation distance is minimised by fabricating channel structures on the heterostructure surface penetrating its active layers. Consequently, a six-fold enhancement of photocurrent conversion efficiency is demonstrated. The proposed hybrid structures offer efficient light harvesting devices where high absorption of the colloidal QDs is utilised and their low charge transfer is overcome.

[1]  Th. Förster,et al.  Transfer Mechanisms of Electronic Excitation Energy , 1960 .

[2]  L Coolen,et al.  Measurement of the radiative and nonradiative decay rates of single CdSe nanocrystals through a controlled modification of their spontaneous emission. , 2004, Physical review letters.

[3]  Pavlos G. Lagoudakis,et al.  Efficient light harvesting in hybrid CdTe nanocrystal/bulk GaAs p-i-n photovoltaic devices , 2009 .

[4]  Pavlos G. Lagoudakis,et al.  Efficient dipole-dipole coupling of Mott-Wannier and Frenkel excitons in (Ga,In)N quantum well/polyfluorene semiconductor heterostructures , 2007 .

[5]  Horst Weller,et al.  Interplay between Auger and ionization processes in nanocrystal quantum dots. , 2005, The journal of physical chemistry. B.

[6]  U. Kortshagen,et al.  Hybrid solar cells from P3HT and silicon nanocrystals. , 2009, Nano letters.

[7]  J. Puls,et al.  Converting Wannier into Frenkel excitons in an inorganic/organic hybrid semiconductor nanostructure. , 2006, Physical review letters.

[8]  Oliver Benson,et al.  Highly Emissive Colloidal CdSe/CdS Heterostructures of Mixed Dimensionality , 2003 .

[9]  Soontorn Chanyawadee,et al.  Resonant energy transfer in light harvesting and light emitting applications , 2009 .

[10]  H. Yeh,et al.  Single-quantum-dot-based DNA nanosensor , 2005, Nature materials.

[11]  Ray Murray,et al.  Hybrid Inorganic/Organic Semiconductor Heterostructures with Efficient Non‐Radiative Energy Transfer , 2006 .

[12]  Donal D. C. Bradley,et al.  Controlled Förster energy transfer in emissive polymer Langmuir-Blodgett structures , 2004 .

[13]  M. Crawford,et al.  Nanocrystal-based light-emitting diodes utilizing high-efficiency nonradiative energy transfer for color conversion. , 2006, Nano letters.

[14]  M. Bawendi,et al.  Synthesis and characterization of nearly monodisperse CdE (E = sulfur, selenium, tellurium) semiconductor nanocrystallites , 1993 .

[15]  M. Henini,et al.  Nonradiative exciton energy transfer in hybrid organic-inorganic heterostructures , 2008 .

[16]  T. K. Woodward,et al.  Measurement of carrier escape rates, exciton saturation intensity, and saturation density in electrically biased multiple-quantum-well modulators , 1994 .

[17]  M D Dawson,et al.  White light emission via cascade Förster energy transfer in (Ga, In)N quantum well/polymer blend hybrid structures. , 2009, Nanotechnology.

[18]  S. Tretiak,et al.  Spectrally resolved dynamics of energy transfer in quantum-dot assemblies: towards engineered energy flows in artificial materials. , 2002, Physical review letters.

[19]  S. R. Forrest,et al.  High-efficiency fluorescent organic light-emitting devices using a phosphorescent sensitizer , 2000, Nature.

[20]  A. Dodabalapur,et al.  Light amplification in organic thin films using cascade energy transfer , 1997, Nature.

[21]  A. Alivisatos.  Semiconductor Clusters, Nanocrystals, and Quantum Dots , 1996, Science.

[22]  Ifor D. W. Samuel,et al.  Distance dependence of excitation energy transfer between spacer-separated conjugated polymer films , 2008 .

[23]  R. Schaller,et al.  High efficiency carrier multiplication in PbSe nanocrystals: implications for solar energy conversion. , 2004, Physical review letters.

[24]  Thomas A. Klar,et al.  Exciton Recycling in Graded Gap Nanocrystal Structures , 2004 .

[25]  A. Nozik.  Quantum dot solar cells , 2002 .

[26]  Darryl L. Smith,et al.  Energy-transfer pumping of semiconductor nanocrystals using an epitaxial quantum well , 2004, Nature.

[27]  R. T. Harley,et al.  Photocurrent enhancement in hybrid nanocrystal quantum-dot p-i-n photovoltaic devices. , 2009, Physical review letters.

[28]  G. Konstantatos,et al.  Solution-processed PbS quantum dot infrared photodetectors and photovoltaics , 2005, Nature materials.

[29]  Pavlos G. Lagoudakis,et al.  Temperature dependence of exciton transfer in hybrid quantum well/nanocrystal heterostructures , 2007 .

[30]  D. Miller,et al.  Room temperature excitonic nonlinear absorption and refraction in GaAs/AlGaAs multiple quantum well structures , 1984 .

[31]  H. Queisser,et al.  Detailed Balance Limit of Efficiency of p‐n Junction Solar Cells , 1961 .

[32]  Christopher B. Murray,et al.  Synthesis and characterization of nearly monodisperse CdE (E = S, Se, Te) semiconductor nanocrystallites , 2005 .

[33]  Marco Finazzi,et al.  Evidence of photoinduced charge transfer in C60/GaAs(1 0 0) bilayers by pump–probe measurements , 2008 .