Integrating GaAs, Si, and Dye-Sensitized Solar Cells in Multijunction Devices and Probing Harsh Condition Behavior

Abstract

Mechanically stacked single illuminated area sequential series multijunction dye-sensitized solar cells (SSM-DSCs) were fabricated with varying bottom devices including DSC, silicon (Si), and gallium arsenide (GaAs). The use of near-infrared (>750 nm) photons for conversion into electricity is probed for each of the three technologies. The effect of using these photons on multijunction device power conversion efficiencies is investigated with a three-subcell SSM-DSC design where the top and middle subcells were DSC devices with D35 and B11 sensitizers, respectively. The power conversion efficiencies were found to follow the order: DSC/DSC/GaAs > DSC/DSC/DSC > DSC/DSC/Si. Low-light conditions were examined for the third subcell technologies as independent solar cells to understand the effects of receiving low light intensity as part of a multijunction system. GaAs and DSC as bottom devices both demonstrated a superior response under filtered or reduced illumination to that of Si in these studies. The influence of harsh temperatures on DSC device performance was also examined.

Lewis Acid–Lewis Base Interactions Promote Fast Interfacial Electron Transfers with a Pyridine-Based Donor Dye in Dye-Sensitized Solar Cells

“…Column chromatography was performed using Sorbent Technologies, Inc. silica gel, porosity 60 Å, 40−63 μm (230 × 400 mesh). 1 H NMR spectra were recorded on a Bruker Avance 400 (400 MHz) spectrometer and reported in ppm using the protiated solvent as an internal standard (CDCl 3 at 7.26 ppm, (CD 3 ) 2 SO at 2.50 ppm, CD 3 CN at 1.94 ppm). Peaks are reported as (s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet; coupling constant (Hz); integration).…”

“…The product was then purified by flash chromatography with silica gel as a thin plug with acetone as the eluent to give the desired product in 64% yield (1.8 g, 5.5 mmol). 1 N-(4-(4,4-Dihexyl-4H-cyclopenta[2,1-b:3,4-b′]dithiophen-2-yl)phenyl)-N-(pyridin-3-yl)pyridin-3-amine (4). Stannylated cyclopentadithiophene 28 (CPDT) 3 (0.58 g, 0.72 mmol), amine 2 (0.20 g, 0.60 mmol), and DMF (2.9 mL) were added into a pressure flask, and the mixture was degassed with N 2 for 30 min.…”

“…(0.44 g, 0.73 mmol). 1 (5). To a flame dried, N 2 filled flask was added anhydrous DMF (5.4 μL, 0.07 mmol), CPDT 4 (40 mg, 0.07 mmol), and dichloroethane (0.2 mL).…”

“…Dye-sensitized solar cells (DSCs) are a relatively low-cost photovoltaic technology with exception performances in practical low-light settings. − These low-light tailored devices are attractive for building integrated photovoltaics − and for use as indoor photovoltaics, which are needed to self-power Internet of Things devices. − DSCs operate with a series of electron transfer events by: (1) photoexcitation of the sensitizer and injection of an electron into TiO 2 , (2) electron transfer from a redox shuttle (RS) to the oxidized dye, and (3) collection of electrons from a counter electrode by the oxidized RS . Increasing the rate of these productive pathways is an attractive approach toward avoiding performance losses due to competitive back electron transfer pathways .…”

Designing Self-Assembled Dye–Redox Shuttle Systems via Interfacial π-Stacking in Dye-Sensitized Solar Cells for Enhanced Low Light Power Conversion

“…Dye-sensitized solar cells (DSCs) are a promising photovoltaic technology, − especially with regard to low light applications − such as with indoor light recycling used to power Internet of Things devices, − underwater applications, building integrated photovoltaics, − and in tandem or multijunction devices. − DSCs operate by (1) photoexcitation of a dye, (2) injection of an electron into a semiconductor such as TiO 2 , (3) regeneration of the neutral dye from the cationic state by electron transfer from a redox shuttle, and (4) collection of an electron at the counter electrode by the oxidized redox shuttle after the electron has traversed an external circuit. The design of dye–redox shuttle systems to improve power conversion efficiencies (PCEs) under low light conditions in DSC devices is needed.…”