The Role of Antireflective Coating CYTOP, Immersion Oil, and Sensitizer Selection in Fabricating a 2.3 V, 10% Power Conversion Efficiency SSM‐DSC Device

Abstract

for maximizing power output from an illuminated area is through the use of multijunction solar cell constructs. [3] Recently, we put forward the first sequential series multijunction dye-sensitized solar cell (SSM-DSC), which could power solarto-fuel conversion directly from a single illuminated area. [4] This construct showed solar-to-fuel conversion efficiencies of up to 3% for CO 2 to CO and H 2 O to H 2 and O 2 reactions in the seminal report of a purely DSC-based technology powering these processes from a single illuminated area device without bias. [4b] The use of a DSC system to power these solar-to-fuel conversion processes is attractive due to the processability, stability, and already relatively high photovoltage outputs from DSC devices. [4a] The SSM-DSC construct capitalizes on the high photovoltages of traditional DSC devices in dividing photons according to potential energy to generate high voltage outputs through a summation of subcell photovoltages. SSM-DSC devices are simple to construct with a direct stacking of subcells sequentially wired in series. In this configuration, devices can be optimized individually in terms of TiO 2 thickness and sensitizer choice to achieve well-matched photocurrents for higher performing SSM-DSC devices since current is limited by the lowest current device in the series. However, within this design, significant light losses exist between each subcell, especially at the glass-air interface where diffraction and reflection are the highest due to significantly mismatched refractive indexes of glass (n = 1.52) and air (n = 1) (Figure 1). To minimize these losses, we put forward the use of a simple-to-apply antireflective coating in the form of CYTOP along with an immersion oil with a similar refractive index to glass between each subcell (Figure 2).CYTOP is known in the field of optoelectronics with recent uses as a gate dielectric, a support layer within devices, as a selfcleaning surface, a solution substrate patterning material, and as an insulating tunneling layer within devices. [5] No reports were apparent from our searches for the specific use of CYTOP as an antireflective coating with organic or dye-sensitized solar cells. The use of CYTOP and immersion oil as optical interfacial loss diminishing components allows for an increase of photon flux throughout the SSM-DSC system to boost photocurrent values for a more overall efficient system. Sequential series multijunction dye-sensitized solar cells (SSM-DSCs) canpower solar-to-fuel processes with a single illuminated area device. Dye selection and strategies limiting photon losses are critical in SSM-DSC devices for higher performance systems. Herein, an efficient and readily applicable spin coating protocol on glass surfaces with an antireflective fluoropolymer (CYTOP) is applied to an SSM-DSC architecture. Combining CYTOP with the use of an immersion oil between glass spacers in a three subcell SSM-DSC with judiciously selected TiO 2 photoanode sensitizers and thicknesses, an overall power conversion efficie...

Waterproof Flexible InP@ZnSeS Quantum Dot Light‐Emitting Diode

“…The transmittances of the CYTOP films at 2000, 3000, and 4000 rpm were 89.7%, 91.2%, and 91.3% at 550 nm, respectively. Interestingly, the transmittance of the bare quartz substrate (88.9%) was slightly lower than that CYTOP coated quartz, in agreement with a previous study . Additionally, we observed no absorbance peaks of core@shell QDs film in the green line spectrum of inset in Figure f, compared to the blue line spectrum (CYTOP/QD film).…”

“…Interestingly, the transmittance of the bare quartz substrate (88.9%) was slightly lower than that CYTOP coated quartz, in agreement with a previous study. [38] Additionally, we observed no absorbance peaks of core@shell QDs film in the green line spectrum of inset in Figure 2f, compared to the blue line spectrum (CYTOP/QD film). QDs film uncoated with CYTOP on the Corning glass was exposed to air for the tranmittance measurement, and we found that absorbance peaks of QDs film without CYTOP were disappeared, indicating unstability of InP@ZnSeS QDs in air.…”

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

“…D35, B11, and Black Dye DSCs were prepared as reported in the literature. 38,56,57 For MK2 (second subcell), B11 (bottom subcell), and AP25 + D35 (bottom subcell) devices, the electrodes were prepared as recently reported. 33,36 Counter Electrode Preparation and Device Assembly.…”

Preferential Direction of Electron Transfers at a Dye–Metal Oxide Interface with an Insulating Fluorinated Self-Assembled Monolayer and MgO

“…The use of insulating metal oxides such as MgO and Al 2 O 3 between the dye and semiconductor to reduce recombination rates has been an active area of research within the DSC field. ,,,− ,− More recently, fluorinated molecules with silyl anchors have been employed as fluorinated self-assembled monolayers (F-SAMs) that coadsorb to the semiconductor in the presence of dyes to reduce recombination sites and lower surface tension (i.e., give a reduction in noncovalent bonding or electrolyte adhesion to the TiO 2 surface). ,− This study seeks to compare these two approaches using a transition metal-based RS ([Co­(bpy) 3 ] 3+/2+ ) used widely in high performing devices and a ruthenium sensitizer ( B11 ) that is one of the highest PCE ruthenium dyes known using I 3 – / I – (Figure ). Notably, with the MgO insulating approach, significant effects on the rates of the injection, BET reaction, and recombination reactions are expected because each of these electron transfers crosses the insulating barrier.…”