Plasmon‐Induced Broadband Light‐Harvesting for Dye‐Sensitized Solar Cells Using a Mixture of Gold Nanocrystals

Abstract

The efficiency of dye-sensitized solar cells (DSSCs) is generally limited by the mismatch between the absorption spectrum of the photosensitizer and the solar irradiation spectrum. This work describes the use of a mixture that containing proper proportions of SiO2 coated Au nanospheres (AuNSs@SiO2 ) and Au nanorods (AuNRs@SiO2 ) (the mixture was denoted as AuNCs@SiO2 ) to enhance the sunlight utility in DSSCs. The incorporation of AuNCs@SiO2 into the TiO2 photoanode induced broadband light-harvesting at both low- and long- wavelengths and thus enhanced the photocurrent compared to that of plasmonic solar cells based on either AuNSs@SiO2 or AuNRs@SiO2 . Upon the doping of AuNCs@SiO2 , the overall power conversion efficiency (PCE) increased from 7.39 to 9.12 % for DSSCs based on organic liquid electrolytes.

Synthesis of Hierarchical TiO2–C3N4 Hybrid Microspheres with Enhanced Photocatalytic and Photovoltaic Activities by Maximizing the Synergistic Effect

“…On the other hand, although TiO 2 is widely used in photocatalysis and photovoltaics, it is only photoactive to UV light as a result of its large band gap (3.2 eV), limiting its practical use (given that visible light accounts for about 50 % of solar energy). TiO 2 is also a state‐of‐the‐art photoanode for DSSCs, having the dual functions of the adsorption of light‐absorbing sensitizers (dyes) and the collection of electrons from incident photons . However, TiO 2 is transparent to many wavelengths at which the dyes absorb, thus hampering efficient sunlight utilization.…”

“…Graphitic carbon nitride (g-C 3 N 4 )i sapromising candidate in photocatalysis and photovoltaics owing to its visible-lightdriven band gap and high stability. [1][2][3][4] However,its photoactivity is still limited by the high electron-hole recombination rate and smalls pecific surface area.O nt he other hand, although TiO 2 is widely used in photocatalysis and photovoltaics, [5][6][7][8][9] it is only photoactive to UV light as ar esult of its large band gap (3.2 eV), limiting its practical use (given that visible light accounts for about5 0% of solare nergy). TiO 2 is also as tate-ofthe-artp hotoanode for DSSCs, having the dual functions of the adsorption of light-absorbing sensitizers (dyes) and the collection of electronsf rom incident photons.…”

“…TiO 2 is also as tate-ofthe-artp hotoanode for DSSCs, having the dual functions of the adsorption of light-absorbing sensitizers (dyes) and the collection of electronsf rom incident photons. [7][8][9] However,T iO 2 is transparent to many wavelengths at which the dyes absorb, thus hampering efficient sunlight utilization.R ecently,c oupling TiO 2 with other semiconductors with an arrow band gap and an egative conduction band provedt ob eauseful strategy to extend the visible-light response of TiO 2 . [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] In addition, this heterojunction also promoted the separation of photoexcited electron-hole pairs by transferring charges from one semiconductor to the other.…”

Sunlight‐Driven Photo‐Thermochromic Smart Windows

“…Considering that solar irradiation spectrum exhibits broadband absorption in visible light region, only using a given AuNRs with a solely wavelength is not enough to increase the temperature when the sample is exposed under the sunlight . Therefore, differently sized Au nanocrystals were mixed together according to our previous reports so that the extinction spectrum of the Au nanocrystal mixture (AuNCs) solution can match better with the solar radiation spectrum and harvest solar energy as much as possible (Figure a) . The cycle tests of the glass substrate, glass substrate with PVA/thermochromic dyes film and glass substrate with PVA/thermochromic dyes/AuNCs film exposing to a solar simulator (AM 1.5G solar irradiation of 100 mW cm −2 ) were recorded in Figure b and c and the absorption spectra of the PVA/dyes/AuNCs films (Figure S3, Supporting Information).…”

“…[20] Therefore, differently sized Au nanocrystals were mixed together according to our previous reports so that the extinction spectrum of the Au nanocrystal mixture (AuNCs) solution can match better with the solar radiation spectrum and harvest solar energy as much as possible (Figure 3a). [20,29] The cycle tests of the glass substrate, glass (Figure 3d), which mean that colorful glass windows in buildings are expected to be achieved.…”