Solar Capacitors Research Articles

Design of high efficiency perovskite solar cells based on inorganic and organic undoped double hole layer

The use of organic and inorganic double hole layers allows for efficient tuning of the matching of energy levels between each layer and improve the photovoltaic performance and stability of perovskite solar cells (PSCs). However, the cost of band matching for preparing perovskite cells is huge. In this paper, the effect of double hole layer on the performance of PSCs is analyzed by theoretical calculation, and an optimized structure of PSCs is proposed. The traditional Spiro-OMeTAD and MAPbI3 absorption layers are added with copper oxide (CuO) hole layers. The Solar Capacitor One-dimensional Tool (SCAPS) is used to simulate the relationship between the energy level matching of the hole layer and the photoelectric conversion efficiency (PCE) of the cell, and then the photovoltaic conversion performance is optimized accordingly. The results show a CuO hole layer with an energy gap of 1.5 can reduce the direct recombination of electron and hole pairs in the recombination layer, thereby increasing the filling factor (FF), while Spiro-OMeTAD can reduce electron recombination in the anode, thereby increasing short circuit current (Jsc). The FF and Jsc is increased simultaneously with the addition of a 200 nm CuO layer, which results in the increase of PCE from 16.82% to 21.82%. In addition, the absorption spectra and power density distributions of the two structures were calculated, and the mechanism of high absorption under different bands was explored. The effect of different material thickness and doping concentration on the photoelectric performance was studied, and the optimal parameters of the solar cell were determined, which increases the PCE by 5.95%. The cell structure proposed in this research can provide theoretical guidance for the development of such experiments and provide a novel design idea for structural optimization of PSCs.

Decoupled Solar Energy Storage and Dark Photocatalysis in a 3D Metal-Organic Framework.

Materials enabling solar energy conversion and long-term storage for readily available electrical and chemical energy are key for off-grid energy distribution. Herein, the specific confinement of a rhenium coordination complex in a metal-organic framework (MOF) unlocks a unique electron accumulating property under visible-light irradiation. About 15C gMOF -1 of electric charges can be concentrated and stored for over four weeks without loss. Decoupled, on-demand discharge for electrochemical reactions and H2 evolution catalysis is shown and light-driven recharging can be conducted for >10 cycles with ≈90% of the initial charging capacity retained. Experimental investigations and theoretical calculations link electron trapping to MOF-induced geometry constraints as well as the coordination environment of the Re-center, highlighting the key role of MOF confinement on molecular guests. This study serves as the seminal report on 3D porous colloids achieving photoaccumulation of long-lived electrons, unlocking dark photocatalysis, and a path toward solar capacitor and solar battery systems.

Monolithic Perovskite Solar Capacitor Enabled by Double-Sided TiO2 Nanotube Arrays

Monolithic Perovskite Solar Capacitor Enabled by Double-Sided TiO₂ Nanotube Arrays

Self-charging flexible solar capacitors based on integrated perovskite solar cells and quasi-solid-state supercapacitors fabricated at low temperature

Self-charging perovskite solar capacitors (SPSCs) that harvest and store solar energy simultaneously can offer sustainable, off-grid power supply for electrical devices. In particular, flexible and lightweight SPSCs are highly desirable in practical applications but are currently restricted by the high annealing temperature needed to make the electron transport layer (ETL) in the devices. Herein, we demonstrate a novel SPSC by integrating a perovskite solar cell (PSC) using amorphous WOx film deposited at room temperature as ETL and a quasi-solid-state supercapacitor (SC). The WOx film with 26 nm thickness yielded a champion power conversion efficiency of 14.14% and 10.80% with the FTO/glass rigid and the ITO/PEN flexible PSCs, respectively. Investigation of the performance of the SPSCs based on the rigid substrate (r-SPSC) and the flexible substrate (f- SPSC) exhibited that the r-SPSC could be photo-charged to 0.68 V within 20 s while the f-SPSC required 25 s to be charged to 0.65 V. Consequently, an overall conversion efficiencies of 2.13% and 1.27% were obtained with the r-SPSCs and the f-SPSC, respectively. This work paves a new way towards making SPSCs that may serve as off-grid electrical power supply in the future.

Bio-photocapacitive tactile sensors as a touch-to-audio braille reader and solar capacitor

Rhodobacter sphaeroidesbased photocapacitive novel touch-to-audio six-pixel tactile sensor that can pronounce the equivalent alphabet.

Photo-Electric Properties of Polypyrrole Based Gel Electrolyte for Hybrid Photoactive Supercapacitors

The nature of solar radiation is not steady, therefore having a solar-capacitor device that can simultaneously capture, convert and store solar energy can promote the technologies using solar energy. A self-charging photoactive supercapacitor is designed and fabricated as a functional solar energy storage device, which is accomplished in situ self-assembled storage technique. The solar-capacitor device is assembled on a multilayered photo-electrode including cationic dye and conducting polymer. The supercapacitor can be charged when the photo-electrode is illuminated. The voltage of the Ppy and Ppy+MB photo-electrodes based devices was increased under illumination effect by 5.22 mV and 23 mV, respectively. The presented results on the hybrid device based Ppy+MB are encouraging for solar-capacitor devices with dual properties of harvesting solar energy and store charges in a single device with two-terminals. With the simplicity of fabrication nanocomposite thin film Ppy+MB, low-cost solar capacitor device can be made for small integrated electronic devices for harvesting and storage energy.

Highly efficient photovoltaic energy storage hybrid system based on ultrathin carbon electrodes designed for a portable and flexible power source

Integrated perovskite solar capacitor (IPSC) systems are the new paradigm for power generation and storage. Herein, a novel configuration and combination of materials for an IPSC, theoretically affording a maximized areal capacitance of 2.35 mF cm−2 and exceeding a 25% overall photo-chemical-electricity energy conversion efficiency is reported. A ∼1 μm solid-state photocapacitor is suggested based on a CH3NH3PbI3 photoactive layer, inorganic buffer junctions, an ultrathin nanocarbon border and top electrodes. For the first time, bulk and interfacial imperfections in the perovskite layer are reckoned in simulation, realizing the recombination rate to 14-order of magnitude higher than that in the perfect perovskite structure. The simulation considers the band gap energy, the valance and conduction bands, carrier mobility and carrier density of every individual layer of the designed IPSC. Overall, the results for the areal capacitance, output voltage and photocharging efficiency under various illumination conditions, frequencies and dielectric materials show that the performance of the perovskite power pack is mildly susceptible to external and internal triggers. This ultrathin and sturdy architecture, shows promise for use in self-powered portable and wearable personal devices.

An all-inorganic perovskite solar capacitor for efficient and stable spontaneous photocharging

Integrated energy “harvesting-storage” devices, especially photocharging devices that can simultaneously achieve the functions of photoelectric energy conversion and electrochemical energy storage, have attracted enormous attention to serve as sustainable and portable distributed power sources. However, the performance of photocharging devices is usually restricted by small voltage plateau and low energy conversion efficiency. Herein, we report a novel “solar capacitor” realized by combining a CsPbBr3 based all-inorganic perovskite solar cell (PSC) and an all-inorganic silica-gel-electrolyte based supercapacitor into a single device. Benefited from the synergy of these two components, the solar capacitor can simultaneously realize the functions of solar power harvesting and electrochemical energy storage without the aid of galvanostatic charging. This device has the merits of compact structure, very fast photocharging rate and high stability, exhibiting a record voltage plateau of 1.2 V and a remarkable overall “photo-electrochemical-electricity” energy conversion efficiency of 5.1%. This work provides new insights for designing novel energy conversion-storage integrated systems.

Integrated perovskite solar capacitors with high energy conversion efficiency and fast photo-charging rate

An integrated perovskite solar capacitor combining a perovskite solar cell and a supercapacitor is developed.

Integrated solar capacitors for energy conversion and storage

Solar energy is one of the most popular clean energy sources and is a promising alternative to fulfill the increasing energy demands of modern society. Solar cells have long been under intensive research attention for harvesting energy from sunlight with a high power-conversion efficiency and low cost. However, the power outputs of photovoltaic devices suffer from fluctuations due to the intermittent instinct of the solar radiation. Integrating solar cells and energystorage devices as self-powering systems may solve this problem through the simultaneous storage of the electricity and manipulation of the energy output. This review summarizes the research progress in the integration of new-generation solar cells with supercapacitors, with emphasis on the structures, materials, performance, and new design features. The current challenges and future prospects are discussed with the aim of expanding research and development in this field.