Highly efficient luminescent solar concentrators based on earth-abundant indirect-bandgap silicon quantum dots

Building-integrated photovoltaics is gaining consensus as a renewable energy technology for producing electricity at the point of use. Luminescent solar concentrators (LSCs) could extend architectural integration to the urban environment by realizing electrode-less photovoltaic windows. Crucial for large-area LSCs is the suppression of reabsorption losses, which requires emitters with negligible overlap between their absorption and emission spectra. Here, we demonstrate the use of indirect-bandgap semiconductor nanostructures such as highly emissive silicon quantum dots. Silicon is non-toxic, low-cost and ultra-earth-abundant, which avoids the limitations to the industrial scaling of quantum dots composed of low-abundance elements. Suppressed reabsorption and scattering losses lead to nearly ideal LSCs with an optical efficiency of η = 2.85%, matching state-of-the-art semi-transparent LSCs. Monte Carlo simulations indicate that optimized silicon quantum dot LSCs have a clear path to η > 5% for 1 m2 devices. We are finally able to realize flexible LSCs with performances comparable to those of flat concentrators, which opens the way to a new design freedom for building-integrated photovoltaics elements. Reabsorption losses in luminescent solar concentrators can be avoided by the use of indirect-bandgap semiconductor nanostructures. The technology has been used to demonstrate flexible luminescent solar concentrators with performance comparable to flat concentrators.

[1]  Benjamin G. Lee,et al.  Quasi-Direct Optical Transitions in Silicon Nanocrystals with Intensity Exceeding the Bulk. , 2016, Nano letters.

[2]  Michael G. Debije,et al.  Solar Energy Collectors with Tunable Transmission , 2010 .

[3]  Hong Ding,et al.  In vivo targeted cancer imaging, sentinel lymph node mapping and multi-channel imaging with biocompatible silicon nanocrystals. , 2011, ACS nano.

[4]  W. V. van Sark,et al.  Long‐term optical stability of fluorescent solar concentrator plates , 2014 .

[5]  Kaifeng Wu,et al.  Doctor-blade deposition of quantum dots onto standard window glass for low-loss large-area luminescent solar concentrators , 2016, Nature Energy.

[6]  Wilfried van Sark,et al.  Tackling self-absorption in Luminescent Solar Concentrators with type-II colloidal quantum dots , 2013 .

[7]  Hybertsen.  Absorption and emission of light in nanoscale silicon structures. , 1994, Physical review letters.

[8]  Ioannis Papakonstantinou,et al.  Flexible and fluorophore-doped luminescent solar concentrators based on polydimethylsiloxane. , 2016, Optics letters.

[9]  Paul P. C. Verbunt,et al.  Effect on the output of a luminescent solar concentrator on application of organic wavelength-selective mirrors. , 2010, Applied optics.

[10]  Luogen Deng,et al.  Ray-trace simulation of CuInS(Se)₂ quantum dot based luminescent solar concentrators. , 2015, Optics express.

[11]  Michael G. Debije,et al.  A comparison of performance of flat and bent photovoltaic luminescent solar concentrators , 2015 .

[12]  W.G.J.H.M. van Sark,et al.  Luminescent solar concentrators – A low cost photovoltaics alternative , 2012 .

[13]  U. Kortshagen,et al.  High-yield plasma synthesis of luminescent silicon nanocrystals. , 2005, Nano letters.

[14]  D. Gamelin,et al.  Nanocrystals for luminescent solar concentrators. , 2015, Nano letters.

[15]  Alex Zunger,et al.  Single-dot absorption spectroscopy and theory of silicon nanocrystals , 2016 .

[16]  L. Manna,et al.  Fabrication and spectroscopic studies on highly luminescent CdSe/CdS nanorod polymer composites , 2010, Beilstein journal of nanotechnology.

[17]  Rebecca J. Anthony,et al.  High-efficiency silicon nanocrystal light-emitting devices. , 2011, Nano letters.

[18]  M. Debije,et al.  Monocrystalline silicon photovoltaic luminescent solar concentrator with 4.2% power conversion efficiency. , 2012, Optics letters.

[19]  Junwei Wei,et al.  Synthesis of Ligand-Stabilized Silicon Nanocrystals with Size-Dependent Photoluminescence Spanning Visible to Near-Infrared Wavelengths , 2012 .

[20]  Uwe R. Kortshagen,et al.  Plasma‐Assisted Synthesis of Silicon Nanocrystal Inks , 2007 .

[21]  D. Gamelin,et al.  Bright CuInS2/CdS nanocrystal phosphors for high-gain full-spectrum luminescent solar concentrators. , 2015, Chemical communications.

[22]  Jaehoon Lim,et al.  Spectroscopic and Device Aspects of Nanocrystal Quantum Dots. , 2016, Chemical reviews.

[23]  Moungi G Bawendi,et al.  Core/shell quantum dot based luminescent solar concentrators with reduced reabsorption and enhanced efficiency. , 2014, Nano letters.

[24]  G. Shao,et al.  An efficient room-temperature silicon-based light-emitting diode , 2001, Nature.

[25]  M. Lannoo,et al.  Electron-phonon coupling and optical transitions for indirect-gap semiconductor nanocrystals , 2001 .

[26]  Michael G. Debije,et al.  Solar Concentrators: Thirty Years of Luminescent Solar Concentrator Research: Solar Energy for the Built Environment (Adv. Energy Mater. 1/2012) , 2012 .

[27]  J. Linnros,et al.  Near-Unity Internal Quantum Efficiency of Luminescent Silicon Nanocrystals with Ligand Passivation. , 2015, ACS nano.

[28]  Yuan Yao,et al.  Luminescent solar concentration with semiconductor nanorods and transfer-printed micro-silicon solar cells. , 2014, ACS nano.

[29]  Tzimas Evangelos,et al.  Critical Metals in Strategic Energy Technologies - Assessing Rare Metals as Supply-Chain Bottlenecks in Low-Carbon Energy Technologies , 2011 .

[30]  Uwe R. Kortshagen,et al.  Silicon nanocrystals with ensemble quantum yields exceeding 60 , 2006 .

[31]  Rebecca J. Anthony,et al.  Photoluminescence quantum yields of amorphous and crystalline silicon nanoparticles , 2009 .

[32]  Daniel R. Gamelin,et al.  Zero-reabsorption doped-nanocrystal luminescent solar concentrators. , 2014, ACS nano.

[33]  P. F. Szajowski,et al.  Quantum Confinement in Size-Selected, Surface-Oxidized Silicon Nanocrystals , 1993, Science.

[34]  Jeslin J. Wu,et al.  Photostability of thermally-hydrosilylated silicon quantum dots , 2015 .

[35]  Michael R. Wasielewski,et al.  Resonance-shifting to circumvent reabsorption loss in luminescent solar concentrators , 2011 .

[36]  Ewan D. Dunlop,et al.  A luminescent solar concentrator with 7.1% power conversion efficiency , 2008 .

[37]  Rebecca J. Anthony,et al.  Routes to Achieving High Quantum Yield Luminescence from Gas‐Phase‐Produced Silicon Nanocrystals , 2011 .

[38]  F. Dimroth,et al.  Increasing the efficiency of fluorescent concentrator systems , 2009 .

[39]  Dongling Ma,et al.  Near Infrared, Highly Efficient Luminescent Solar Concentrators , 2016 .

[40]  J. Lambe,et al.  Luminescent greenhouse collector for solar radiation. , 1976, Applied optics.

[41]  George C Schatz,et al.  On the origin of photoluminescence in silicon nanocrystals: pressure-dependent structural and optical studies. , 2012, Nano letters.

[42]  A. Goetzberger,et al.  Solar energy conversion with fluorescent collectors , 1977 .

[43]  Hunter McDaniel,et al.  Highly efficient large-area colourless luminescent solar concentrators using heavy-metal-free colloidal quantum dots. , 2015, Nature nanotechnology.

[44]  Paul P. C. Verbunt,et al.  Thirty Years of Luminescent Solar Concentrator Research: Solar Energy for the Built Environment , 2012 .

[45]  Stephan Lüttjohann,et al.  Silicon nanoparticles: Absorption, emission, and the nature of the electronic bandgap , 2007 .

[46]  Sergio Brovelli,et al.  Large-area luminescent solar concentrators based on ‘Stokes-shift-engineered’ nanocrystals in a mass-polymerized PMMA matrix , 2014, Nature Photonics.

[47]  Kirk J. Ziegler,et al.  Highly luminescent silicon nanocrystals with discrete optical transitions. , 2001, Journal of the American Chemical Society.