Quantum junction solar cells.

Colloidal quantum dot solids combine convenient solution-processing with quantum size effect tuning, offering avenues to high-efficiency multijunction cells based on a single materials synthesis and processing platform. The highest-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO(2)); however, quantum tuning of the absorber then requires complete redesign of the bulk acceptor, compromising the benefits of facile quantum tuning. Here we report rectifying junctions constructed entirely using inherently band-aligned quantum-tuned materials. Realizing these quantum junction diodes relied upon the creation of an n-type quantum dot solid having a clean bandgap. We combine stable, chemically compatible, high-performance n-type and p-type materials to create the first quantum junction solar cells. We present a family of photovoltaic devices having widely tuned bandgaps of 0.6-1.6 eV that excel where conventional quantum-to-bulk devices fail to perform. Devices having optimal single-junction bandgaps exhibit certified AM1.5 solar power conversion efficiencies of 5.4%. Control over doping in quantum solids, and the successful integration of these materials to form stable quantum junctions, offers a powerful new degree of freedom to colloidal quantum dot optoelectronics.

[1]  A Paul Alivisatos,et al.  Photovoltaic devices employing ternary PbSxSe1-x nanocrystals. , 2009, Nano letters.

[2]  E. Sargent.  Infrared photovoltaics made by solution processing , 2009 .

[3]  Jianbo Gao,et al.  Quantum dot size dependent J-V characteristics in heterojunction ZnO/PbS quantum dot solar cells. , 2011, Nano letters.

[4]  A Paul Alivisatos,et al.  Photovoltaic performance of ultrasmall PbSe quantum dots. , 2011, ACS nano.

[5]  Charles Howard Henry,et al.  Limiting efficiencies of ideal single and multiple energy gap terrestrial solar cells , 1980 .

[6]  Lukasz Brzozowski,et al.  Quantum dot photovoltaics in the extreme quantum confinement regime: the surface-chemical origins of exceptional air- and light-stability. , 2010, ACS nano.

[7]  Byung-Ryool Hyun,et al.  Electron injection from colloidal PbS quantum dots into titanium dioxide nanoparticles. , 2008, ACS nano.

[8]  V. Bulović,et al.  Colloidal PbS quantum dot solar cells with high fill factor. , 2010, ACS nano.

[9]  Matt Law,et al.  Schottky solar cells based on colloidal nanocrystal films. , 2008, Nano letters.

[10]  Ghada I. Koleilat,et al.  Electron Acceptor Materials Engineering in Colloidal Quantum Dot Solar Cells , 2011, Advanced materials.

[11]  Dmitri V Talapin,et al.  PbSe Nanocrystal Solids for n- and p-Channel Thin Film Field-Effect Transistors , 2005, Science.

[12]  Marco Califano,et al.  Size-dependent valence and conduction band-edge energies of semiconductor nanocrystals. , 2011, ACS nano.

[13]  E. Aydil,et al.  Solar cells based on junctions between colloidal PbSe nanocrystals and thin ZnO films. , 2009, ACS nano.

[14]  Edward H. Sargent,et al.  Impact of dithiol treatment and air annealing on the conductivity, mobility, and hole density in PbS colloidal quantum dot solids , 2008 .

[15]  Aram Amassian,et al.  Colloidal-quantum-dot photovoltaics using atomic-ligand passivation. , 2011, Nature materials.

[16]  Martin A. Green,et al.  Solar cell efficiency tables (version 39) , 2012 .

[17]  V. Bulović,et al.  Control of the carrier type in InAs nanocrystal films by predeposition incorporation of Cd. , 2010, ACS nano.

[18]  Jianbo Gao,et al.  n-Type transition metal oxide as a hole extraction layer in PbS quantum dot solar cells. , 2011, Nano letters.

[19]  Enhanced open-circuit voltage in visible quantum dot photovoltaics by engineering of carrier-collecting electrodes. , 2011, ACS applied materials & interfaces.

[20]  Moungi G Bawendi,et al.  Improved current extraction from ZnO/PbS quantum dot heterojunction photovoltaics using a MoO3 interfacial layer. , 2011, Nano letters.

[21]  Gregory D. Scholes,et al.  Colloidal PbS Nanocrystals with Size‐Tunable Near‐Infrared Emission: Observation of Post‐Synthesis Self‐Narrowing of the Particle Size Distribution , 2003 .

[22]  Edward H Sargent,et al.  Colloidal quantum dot photovoltaics: a path forward. , 2011, ACS nano.

[23]  D. S. Bradshaw,et al.  Photonics , 2023, 2023 International Conference on Electrical Engineering and Photonics (EExPolytech).

[24]  Edward H. Sargent,et al.  Tandem colloidal quantum dot solar cells employing a graded recombination layer , 2011 .