Hybrid Thin Film Solar Cell Research Articles

Morphology Control of Monomer-Polymer Hybrid Electron Acceptor for Bulk-Heterojunction Solar Cell Based on P3HT and Ti-Alkoxide with Ladder Polymer.

We report the morphology control of a nano-phase-separated structure in the photoactive layer (power generation layer) of organic–inorganic hybrid thin-film solar cells to develop highly functional electronic devices for societal applications. Organic and inorganic–organic hybrid bulk heterojunction solar cells offer several advantages, including low manufacturing costs, light weight, mechanical flexibility, and a potential to be recycled because they can be fabricated by coating them on substrates, such as films. In this study, by incorporating the carrier manager ladder polymer BBL as the third component in a conventional two-component power generation layer consisting of P3HT—the conventional polythiophene derivative and titanium alkoxide—we demonstrate that the phase-separated structure of bulk heterojunction solar cells can be controlled. Accordingly, we developed a discontinuous phase-separated structure suitable for charge transport, obtaining an energy conversion efficiency higher than that of the conventional two-component power generation layer. Titanium alkoxide is an electron acceptor and absorbs light with a wavelength lower than 500 nm. It is highly sensitive to LED light sources, including those used in homes and offices. A conversion efficiency of 4.02% under a 1000 lx LED light source was achieved. Hence, high-performance organic–inorganic hybrid bulk heterojunction solar cells with this three-component system can be used in indoor photovoltaic systems.

High efficient hybrid bulk hetero junction thin-film solar cell embedded with kesterite Cu2ZnSnS4 quantum dots

The photovoltaic performance of kesterite Cu 2 ZnSnS 4 (CZTS) quantum dot (QD) incorporated poly(3-hexylthiophene-2,5-diyl) (Alvarado et al., 1998; Alvarado et al., 1998) [6,6]: phenyl-C61butyric acid hexyl ester (P3HT:PCBH) polymer matrix based organic hybrid heterojunction solar cell configuration is investigated. The inorganic filler material CZTS QDs with P3HT:PCBH matrix, forms double bulk hetero junction (BHJ) throughout in the active layer, which facilitates rapid exciton dissocitaion process at P3HT:PCBH and CZTS:PCBH interfaces that results effective charge carrier separation. The prepared active layer material has been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), Raman and fourier transform infra red (FTIR). The enhanced optical absorbance of prepared hybrid structure has been verified by UV–Visible analysis. It has been observed that the improvement in photo conversion efficiency (PCE) from 2.36% for the solar cell device P3HT:PCBH to 4.12% for CZTS QD based P3HT:PCBH hybrid organic solar cell device. This dramtaic increase in PCE, is mainly due to the significant enhancement in short-circuit current density (J sc ) from 7.6 mA/cm 2 to 11.2 mA/cm 2 . That suggests, the incorporation of p-type kesterite CZTS QDs into P3HT:PCBH polymer matrix enhances the effective exciton dissociation at interfaces resulting charge separation and their fast extraction to electrodes inhibiting e − /h + pair recombination. Furthermore, the hybrid solar cell shows remarkable time stability retaining 80% of original PCE measured after 30 days under ambient environment conditions. The hybrid organic solar cell device shows thermal stability by retaining 95.6% of its intial efficiency measured which has been tested in the temperature range 20–80 °C. • Photovoltaic performance of CZTS QDs:P3HT:PCBH hybrid thin film solar cell is investigated. • PCE of hybrid device has been observed to enhance from 2.36% to 4.12%. • It shows time and thermal stability retaining 80% and 95.6% efficiency.

Development of organic/inorganic PANI/ZnO 1D nanostructured hybrid thin film solar cell by soft chemical route

Polyaniline (PANI)/zinc oxide (ZnO) nanorods hybrid solar cell device was fabricated via a two-step process. The first step involved soft chemical synthesis of ZnO nanorods thin film on the indium-doped tin oxide (ITO) substrate and subsequent annealing in air at 300 °C. The second step of involved chemisorption of PANI on the surface of the ZnO nanorods by Doctor Blade Method. The fabricated heterojunction films were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), fourier transform infrared (FT-IR), and Raman spectra. The results confirmed chemical interactions between PANI and ZnO and thus the formation of the heterojunction. Both the PANI coated pristine and annealed ZnO nanorods thin films were studied for their solar cell characteristics. The results of solar cell measurements showed that the overall light-conversion efficiency of PANI coated pristine ZnO thin film to be ~ 80% higher than for PANI coated annealed ZnO thin film. This is attributed to more effective charge separation and faster interfacial charge transferring occurred in the pristine ZnO thin films.

Enhanced charge carrier generation by dielectric nanomaterials for quantum dots solar cells based on CdS-TiO2 photoanode

This paper reports an inclusive study of synthesis and characterization of quantum dots CdS embedded Pb0.85La0.15TiO3 (PLT15) dielectric nanocomposite materials for application in thin-film quantum dots solar cells (QDSSc). We have synthesized dielectric materials which act as a strong field-effect passivation, screened columbic attraction, back reflector and recombination inhibitor for solar cell fabrication. This material was deposited on FTO/TiO2 layer with a uniform mixed layer of nanorod (CdS)-nanoparticles (PLT15) which result in an increase in the SCs efficiency by times higher from the reference value. By adding dielectric materials in a prototype solar cell, an enhancement of 6.32mA/cm2 in short-circuit current and an absolute value of 4.5% enhancement in overall conversion efficiency are achieved. In particular, synthesis of materials, fabrication, structural, optical, electrical and stability of the prototype SCs are examined thoroughly. We also performed a detailed investigation of aging on the main characteristics of solar cells, such as efficiency, fill factor, short circuit current and open circuit voltage. It was observed that due to its cost effectiveness, stability, and enhance efficiency, this dielectric based hybrid thin film solar cells have high potential to be applied in industry in the near future.

A rational elemental-directed alcohol-thermal route to CdSe nanostructures for thin film solar cells

We have reported an alcohol-thermal method to in-situ synthesis of Cadmium Selenide (CdSe) nanocrystals/thin films on Cd/indium-doped tin oxide (ITO) substrates through a direct reaction of Se and Cd. In the synthetic system, ligands and surfactants are not introduced, and concentration of reaction precursors is not high, thus not only it is a very economic and environmental-friendly route, but also the CdSe film without any impurities is obtained. The Cd deposited on ITO substrates by magnetron sputtering acted as dual roles: reactant source and hard template for the final product. The microstructure is analyzed by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). Poly(3-hexylthiophene) (P3HT) is deposited on CdSe film to fabricate a hybrid thin film solar cell device with ITO/CdSe/P3HT/Al structure to demonstrate solar light to electrical energy conversion.

Nanotetrapods: quantum dot hybrid for bulk heterojunction solar cells.

Hybrid thin film solar cell based on all-inorganic nanoparticles is a new member in the family of photovoltaic devices. In this work, a novel and performance-efficient inorganic hybrid nanostructure with continuous charge transportation and collection channels is demonstrated by introducing CdTe nanotetropods (NTs) and CdSe quantum dots (QDs). Hybrid morphology is characterized, demonstrating an interpenetration and compacted contact of NTs and QDs. Electrical measurements show enhanced charge transfer at the hybrid bulk heterojunction interface of NTs and QDs after ligand exchange which accordingly improves the performance of solar cells. Photovoltaic and light response tests exhibit a combined optic-electric contribution from both CdTe NTs and CdSe QDs through a formation of interpercolation in morphology as well as a type II energy level distribution. The NT and QD hybrid bulk heterojunction is applicable and promising in other highly efficient photovoltaic materials such as PbS QDs.

Organic-inorganic hybrid thin film solar cells using conducting polymer and gold nanoparticles

We employed poly(styrenesulfonate)-doped poly (3,4-ethylenedioxythiophene) (PEDOT:PSS) as a p-layer on textured fluorine-tin-oxide (FTO) glass in pin-type hydrogenated amorphous silicon solar cells (a-Si:H SCs). An amorphous tungsten oxide (WO3) layer and gold nanoparticles (Au-NPs) 10 nm in size were included to prevent the degradation and to increase short-circuit current by the Plasmon effect, respectively, between the PEDOT:PSS and intrinsic-Si layer. The energy band between PEDOT:PSS and WO3 was meaningfully adjusted by Au-NPs. The p-type PEDOT:PSS layer in these organic-inorganic hybrid a-Si:H SCs results in an increased conversion efficiency from ∼2.42% to ∼5.49% and an increased open-circuit voltage from ∼0.29 V to ∼0.56 V. PEDOT:PSS on textured FTO glass is sufficiently showing that it can replace the p-type Si layer in pin-type a-Si:H SCs.

Highly efficient hybrid thin-film solar cells using a solution-processed hole-blocking layer

We report the origin of the improvement of the power conversion efficiency (PCE) of hybrid thin-film solar cells when a soluble C(60) derivative, [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM), is introduced as a hole-blocking layer. The PCBM layer could establish better interfacial contact by decreasing the reverse dark-saturation current density, resulting in a decrease in the probability of carrier recombination. The PCE of this optimized device reached a maximum value of 8.34% and is the highest yet reported for hybrid thin-film solar cells.

Preparation and characterization of P3HT:CuInSe 2:TiO 2 thin film for hybrid solar cell applications

Improved efficiency of hybrid Al/Ca/P3HT:CISe:TiO 2/PEDOT:PSS/ITO thin film solar cells was obtained by optimizing P3HT/CISe ratio. This study also investigated the effects of TiO 2 content in the P3HT:CISe active layer, and altering annealing temperature conditions. The optimum TiO 2 content and annealing temperature for solar cell efficiency is 25 wt.% and 150 °C, respectively. The optimal results for the open circuit voltages (V OC), short-circuit current density (J SC), fill factor (FF), and efficiency (η) of the prepared hybrid thin film solar cell were V OC = 0.335 V, J SC = 8.07 mA/cm 2, FF = 52.75, and η = 1.425.

In situ fabrication of chalcogenide nanoflake arrays for hybrid solar cells: the case of In2S3/poly(3-hexylthiophene)

A novel strategy for fabricating hybrid thin film solar cell devices based on poly(3-hexylthiophene) (P3HT)/indium sulfide (In2S3) nanoflake array films is presented in this paper. We take In2S3 as an example to demonstrate that a novel chalcalgenide nanoflake array structure could be in situ fabricated on indium-tin oxide (ITO) glass substrates through a one-step solvothermal treatment of an indium nanocrystal layer and sulfur powder in the presence of absolute ethanol. The resulting products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and UV-vis spectrophotometry. A preliminary photovoltaic performance measurement of the fabricated device (ITO/PEDOT:PSS/In2S3:P3HT/Al) shows a short circuit current density (Jsc) of 0.68 mA cm−2 and a power conversion efficiency (η) of 0.04% under an illumination of 100 mW cm−2. The in situ-fabricated special nanoflake array structure may provide a large interfacial surface area for the In2S3 nanocrystals and the poly(3-hexylthiophene) in such hybrid solar cell devices. This novel wet chemical strategy may remove the need for insulated surfactants, improve the stability of both the thin film and the fabricated device, and is expected to be expanded to fabricate other conjugated polymer/charcalgenide hybrid thin film solar cell devices.

Ultra-lightweight space power from hybrid thin-film solar cells

The development of hybrid inorganic/organic thin-film solar cells on flexible, lightweight, space-qualified, durable substrates provides an attractive solution for space power generation with high mass specific power (W/kg). The high-volume, low-cost fabrication potential of organic cells will allow for square miles of solar cell production at one-tenth the cost of conventional inorganic materials. Plastic solar cells take a minimum of storage space and can be inflated or unrolled for deployment. We explore a cross-section of NASA in-house and sponsored research efforts that aim to provide new hybrid technologies that include both inorganic and polymer materials as active and substrate materials. For NASA applications, any solar cell or array technology must not only meet weight and AMO efficiency goals, but also must be durable enough to survive launch and space environments. Also, balance of system technologies must be developed to take advantage of ultra-lightweight solar arrays in power generation systems.