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1.
Small ; 19(52): e2305246, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37635119

RESUMEN

Pure δ-formamidinium lead triiodide (δ-FAPbI3 ) single crystal for highly efficient perovskite solar cell (PCS) with long-term stability is prepared by a new method consisting of liquid phase reaction of FAI and PbI2 in N,N-dimethyl formamide and antisolvent crystallization using acetonitrile. In this method, the incorporation of any impurity into the crystal is excluded by the molecular recognition of the crystal growth site. This pure crystal is used to fabricate α-FAPbI3 inverted PSCs which showed excellent power conversion efficiency (PCE) due to much-reduced trap-states. The champion device exhibited a high PCE of 23.48% under the 1-Sun condition. Surface-treated devices with 3-(aminomethyl)pyridine showed a significantly improved PCE of 25.07%. In addition, the unencapsulated device maintained 97.22% of its initial efficiency under continuous 1-Sun illumination for 1,000 h at 85 °C in an N2 atmosphere ensuring long-term thermal and photo stabilities of PSCs, whereas the control device kept only 89.93%.

2.
J Org Chem ; 83(5): 2640-2646, 2018 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-29457900

RESUMEN

A new deep-blue chromophore containing a three-dimensionally (3D) shaped CS core composed of fused chrysene and spirofluorene units is synthesized. A pair of m-terphenyl (TP) units is also substituted onto the CS core at two different sets of positions to form two additional compounds: CS-TPTP and TP-CS-TP. The TP-CS-TP compound showed the highest efficiency with an external quantum efficiency (EQE) of 3.05% and Commission Internationale de L'Eclairage coordinates (CIE) of (0.148, 0.098) corresponding to the emission of blue light. This approach for forming a new chromophore is expected to lead to the development of functional organic materials with excellent characteristics.

3.
Nanotechnology ; 27(2): 024004, 2016 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-26618542

RESUMEN

Bilayer type CH3NH3PbI3 (MAPbI3) perovskite hybrid solar cells were fabricated via a one-step spin-coating process by using solubility controlled MAPbI3 solutions of MAPbI3-DMSO (dimethyl sulfoxide) and MAPbI3-DMF (N, N-dimethylformamide)-HI. The best DMSO-bilayer device showed 1.07 ± 0.02 V V(oc) (open-circuit voltage), 20.2 ± 0.1 mA cm(-2) J(sc) (short-circuit current density), 68 ± 2% FF (fill factor), and 15.2 ± 0.3% η (overall power conversion efficiency) under the forward scan direction and 1.07 ± 0.02 V V(oc), 20.4 ± 0.1 mA cm(-2) J(sc), 70 ± 3% FF, and 15.9 ± 0.4% η under the reverse scan direction. The best HI-bilayer device had 1.08 ± 0.02 V V(oc), 20.6 ± 0.1 mA cm(-2) J(sc), 75 ± 1% FF, and 17.2 ± 0.2% η under the forward scan direction and 1.08 ± 0.02 V V(oc), 20.6 ± 0.1 mA cm(-2) J(sc), 76 ± 2% FF, and 17.4 ± 0.3% η under the reverse scan direction. The deviation of average device efficiency (η(avg)) of 20 DMSO samples and 20 HI samples was 14.2 ± 0.95% and 16.2 ± 0.85%, respectively. Therefore, the HI-bilayer devices exhibited better device efficiency and smaller J-V (current density-voltage) hysteresis with respect to the scan direction than the DMSO-bilayer devices due to the reduced recombination and traps by the formation of a purer and larger MAPbI3 perovskite crystalline film.

4.
Nano Lett ; 13(4): 1764-9, 2013 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-23517331

RESUMEN

Chemically tuned inorganic-organic hybrid materials, based on CH3NH3(═MA)Pb(I(1-x)Br(x))3 perovskites, have been studied using UV-vis absorption and X-ray diffraction patterns and applied to nanostructured solar cells. The band gap engineering brought about by the chemical management of MAPb(I(1-x)Br(x))3 perovskites can be controllably tuned to cover almost the entire visible spectrum, enabling the realization of colorful solar cells. We demonstrate highly efficient solar cells exhibiting 12.3% in a power conversion efficiency of under standard AM 1.5, for the most efficient device, as a result of tunable composition for the light harvester in conjunction with a mesoporous TiO2 film and a hole conducting polymer. We believe that the works highlighted in this paper represent one step toward the realization of low-cost, high-efficiency, and long-term stability with colorful solar cells.


Asunto(s)
Compuestos de Calcio/química , Nanoestructuras/química , Óxidos/química , Energía Solar , Titanio/química , Rayos Ultravioleta
5.
Nanomicro Lett ; 15(1): 114, 2023 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-37121936

RESUMEN

Here, we report a mixed GAI and MAI (MGM) treatment method by forming a 2D alternating-cation-interlayer (ACI) phase (n = 2) perovskite layer on the 3D perovskite, modulating the bulk and interfacial defects in the perovskite films simultaneously, leading to the suppressed nonradiative recombination, longer lifetime, higher mobility, and reduced trap density. Consequently, the devices' performance is enhanced to 24.5% and 18.7% for 0.12 and 64 cm2, respectively. In addition, the MGM treatment can be applied to a wide range of perovskite compositions, including MA-, FA-, MAFA-, and CsFAMA-based lead halide perovskites, making it a general method for preparing efficient perovskite solar cells. Without encapsulation, the treated devices show improved stabilities.

6.
Phys Chem Chem Phys ; 14(43): 14999-5002, 2012 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-23034567

RESUMEN

PbS colloidal quantum dot (CQD)-sensitized inorganic-organic heterojunction solar cells fabricated by using the PbS CQDs co-capped by the oleic acid (OA) and 1-dodecanethiol (DT) ligand showed better device stability with aging time under ambient conditions without encapsulation. Furthermore, the device performance is better than the cell fabricated from PbS CQDs without DT ligand. The enhancement of performance in OA and DT co-capped systems is investigated by impedance spectroscopy. An upward displacement of the TiO(2) conduction band, with a consequent increase of V(oc), results in the improved performance when CQD with DT are employed.

7.
ACS Appl Mater Interfaces ; 14(6): 7926-7935, 2022 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-35041387

RESUMEN

Spray-coating is a scalable and time-efficient technique for the development of large-area metal halide perovskite (MHP) solar cells. However, a bottleneck still exists toward the development of fully scalable n-i-p-type MHP solar cells particularly on spray-coating the hole transporting layer (HTL). Here, we present a reliable strategy of spray-coating the HTL by using MoO2 nanoparticles with small amounts of poly(triarylamine) (PTAA) binders to ensure uniform coverage and efficient charge extraction. By spray-coating all layers except the Au electrode, we achieve high and scalable efficiencies of 14.26 and 13.88% for CsPbI2Br unit cells (0.12 cm2) and submodules (25 cm2), respectively. We then extend toward an all-spray-coating process by spray-coating carbon black as the top counter electrode, resulting in a submodule efficiency of 10.08%. Finally, we also demonstrate good long-term stability of the submodules under damp heat conditions (85 °C/85% relative humidity) over 1000 h.

8.
iScience ; 24(8): 102927, 2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-34430816

RESUMEN

Perovskite materials have demonstrated superior performance in many aspects of optoelectronic applications including X-ray scintillation, photovoltaic, photodetection, and so on. In this work, we demonstrate a self-powered flexible all-perovskite X-ray detector with high sensitivity and fast response, which can be realized by integrating CsPbBr3 perovskite nanocrystals (PNCs) as the X-ray scintillator with a CH3NH3PbI3 perovskite photodetector. The PNCs scintillator exhibits ultra-fast light decay of 2.81 ns, while the perovskite photodetector gives a fast response time of ∼0.3 µs and high-specific detectivity of ∼2.4×1012 Jones. The synergistic effect of these two components ultimately leads to a self-powered flexible all-perovskite X-ray detector that delivers high sensitivity of 600-1,270 µC/mGyaircm3 under X-ray irradiation and fast radiation-to-current response time.

9.
ACS Appl Mater Interfaces ; 13(14): 16775-16783, 2021 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-33787223

RESUMEN

Enhancement in weak-light detection and other photodetection properties was observed for organic-inorganic halide perovskite photodetectors as a result of benzylammonium iodide (BzAI) treatment at the methylammonium lead triiodide (MAPbI3) and hole-transport layer (HTL) interface. After treatment, growth of the two-dimensional Ruddlesden-Popper perovskite phase was observed at the MAPbI3 surface, which shifted the overall surface work function upwards and thus effectively facilitated charge transfer across the MAPbI3/HTL interface. As a result, the fully fabricated device with 10 mg/mL (BzAI/isopropanol) treatment exhibited shorter rise time (trise) and decay time (tdecay) of 53 and 38 µs, respectively, compared to trise and tdecay of 214 and 120 µs, respectively, for the pristine MAPbI3 sample. In addition, the BzAI-treated device exhibited larger linearity compared to the pristine MAPbI3 sample, demonstrating a high and stable specific detectivity of 1.49 × 1013 to 2.14 × 1013 Jones under incident light intensity of 10-3 to 100 mW/cm2, respectively.

10.
RSC Adv ; 10(56): 33651-33661, 2020 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-35519056

RESUMEN

A void-free metal halide perovskite (MHP) layer on a mesoscopic TiO2 (m-TiO2) film was formed via the wetting-induced infiltration of MHP solution in the m-TiO2 film via a green ultrasonic spray coating process using a non-hazardous solvent. The systematic investigation of the behavior of ultrasonic-sprayed MHP micro-drops on the m-TiO2 film disclosed that the void-free MHP layer on the m-TiO2 film can be formed if the following conditions are satisfied: (1) the sprayed micro-drops are merged and wetted in the mesoscopic scaffold of the m-TiO2 film, (2) the MHP solution infiltrated into the m-TiO2 film by wetting is leveled to make a smooth wet MHP film, and (3) the smooth wet MHP film is promptly heat treated to eliminate dewetting and the coffee ring effect by convective flow in order to form a uniform void-free MHP layer. A void-free MHP layer on the m-TiO2 film was formed under optimal ultrasonic spray coating conditions of substrate temperature of ∼30 °C, spray flow rate of ∼11 mL h-1, nozzle to substrate distance of ∼8 cm, and MHP solution-concentration of ∼0.6 M under a fixed scan speed of 30 mm s-1 and purged N2 carrier gas pressure of 0.02 MPa. The mesoscopic MHP solar cells with an aperture area of 0.096, 1, 25, and 100 cm2 exhibited 17.14%, 16.03%, 12.93%, and 10.67% power conversion efficiency at 1 sun condition, respectively.

11.
ACS Appl Mater Interfaces ; 12(7): 8233-8239, 2020 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-31977182

RESUMEN

PbI2(DMSO) complex powder, which is essential to fabricate efficient metal halide perovskite solar cells (MHP SCs), was synthesized by liquid phase solvent extraction process irrespective of reaction volume scale. The isopropanol (IPA) solvent could selectively extract the DMSO from PbI2(DMSO)2 powder during extraction process so that compositionally uniform PbI2(DMSO) powder could be obtained in a large scale process, whereas the vacuum drying process could not produce uniform PbI2(DMSO) powder. Due to the compositional uniformity of PbI2(DMSO) powders prepared by solvent extraction process, the MHP SCs could be fabricated very reproducibly.

12.
ACS Appl Mater Interfaces ; 12(1): 886-892, 2020 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-31813222

RESUMEN

Vertically aligned TiO2 nanorod (NR) electrodes with straight macropores enabled a metal halide perovskite (MHP) solution to be fully infiltrated within their structure and, as a result, formed void-free dense MHP films reproducibly during an electrospray-coating process, whereas conventional mesoporous TiO2 (m-TiO2) electrodes with three-dimensionally interconnected mesopores formed internal voids by imperfect infiltration of MHP solution. Hence, TiO2 NR-based MHP solar cells could be more reproducibly fabricated by an electrospray-coating process and exhibited smaller current density-voltage hysteresis with respect to the scan direction and scan rate than the m-TiO2-based MHP solar cells due to the short and straight electron pathway either by a one-dimensional TiO2 NR electrode or a densely formed MHP layer within the TiO2 NR electrode.

13.
RSC Adv ; 10(30): 17724-17730, 2020 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-35515599

RESUMEN

Structure engineering of trivalent metal halide perovskites (MHPs) such as A3Sb2X9 (A = a monovalent cation such as methyl ammonium (MA), cesium (Cs), and formamidinium (FA) and X = a halogen such as I, Br, and Cl) is of great interest because a two dimensional (2D) layer structure with direct bandgap has narrower bandgap energy than a zero dimensional (0D) dimer structure with indirect bandgap. Here, we demonstrated 2D layer structured FACs2Sb2I6Cl3 MHP by dual-site (A and X site) mixing. Thanks to the lattice-symmetry change by I-Cl mixed halide, the shortest ionic radius of Cs, and the lower solution energy due to dual-site mixing, the FACs2Sb2I6Cl3 MHP had 2D layer structure and thereby the MHP solar cells exhibited improved short-circuit current density.

14.
ACS Appl Mater Interfaces ; 12(9): 10527-10534, 2020 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-32048829

RESUMEN

A semitransparent flexible metal halide perovskite (MHP) solar cells were demonstrated by reproducible dry stamping transfer of a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS, PH1000) transparent flexible top electrode onto poly(ethylene terephthalate) (PET)/indium tin oxide (ITO)/PEDOT:PSS (AI4083)/MHP/[6,6]-phenyl-C61-butyric acid methyl ester (PCBM). The reproducible transfer of the PEDOT:PSS top electrode was enabled by the modification of PEDOT:PSS with poly(ethylene imine) (PEI)/2-methoxyethanol (2-MEA) solution. In addition, the PEI/2-MEA modification to PEDOT:PSS resulted in improved conductivity and reduced work function of the top electrode. Therefore, we could fabricate highly efficient flexible semitransparent MHP solar cells with >13% (active area = 1 cm2) power conversion efficiency.

16.
ACS Appl Mater Interfaces ; 11(21): 19123-19131, 2019 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-31070346

RESUMEN

High-performance and hysteresis-less mesoscopic CsPbI2Br perovskite solar cells (PSCs) are demonstrated by adapting hole-transporting materials (HTMs) with controlled highest occupied molecular orbital (HOMO) values. The used model HTMs are poly-3-hexylthiophene (P3HT), poly-triarylamine (P-TAA), poly-fluoren-8-triarylamine (PF8-TAA), and poly-indenofluoren-8-triarylamine (PIF8-TAA), and their HOMO energy levels position to -4.98, -5.09, -5.45, and -5.52 eV, respectively. By controlling the HOMO of the HTMs, the average open-circuit voltages of 25 mesoscopic CsPbI2Br PSCs are controllable from 1.11 ± 0.030 V for a P3HT HTM-based device to 1.17 ± 0.023, 1.21 ± 0.027, and 1.27 ± 0.028 V for P-TAA, PF8-TAA, and PIF8-TAA HTM-based devices. As a result, the PIF8-TAA HTM-based mesoscopic PSC exhibits the highest open-circuit voltage of 1.31 V and power conversion efficiency (PCE) of 14.20% for the forward scan condition and 14.86% for the reverse scan condition under 1 sun illumination (100 mW/cm2 AM 1.5G). In addition, the unencapsulated mesoscopic CsPbI2Br PSCs exhibited 10-14% of PCE degradation compared to their initial efficiency in maximum power point tracking under continuous 1 sun light soaking at 85 °C for 1000 h.

17.
ACS Appl Mater Interfaces ; 11(46): 43066-43074, 2019 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-31657896

RESUMEN

Highly efficient and thermally stable inorganic CsPbI2Br mesoscopic metal halide perovskite (MHP) solar cells with a poly-3-hexylthiophene (P3HT) hole transporting layer (HTL) are demonstrated by spin-washing of the P3HT HTL since the light harvesting efficiency is improved by minimizing the coabsorption of light by P3HT, and the open-circuit voltage is enhanced because of the increased valence band maximum position of the spin-washed P3HT HTL. The spin-washed CsPbI2Br MHP solar cell exhibited 1.24 V open-circuit voltage (Voc), 14.20 mA/cm2 short-circuit current density (Jsc), 81.52% fill factor (FF), and 14.35% power conversion efficiency (PCE). The unencapsulated spin-washed CsPbI2Br MHP solar cell went through 7.56% degradation after a 1000 h thermal stability test under 100 °C/25% relative humidity (RH) and simultaneous 1 sun light soaking conditions. In addition, the unencapsulated spin-washed CsPbI2Br MHP solar submodule with 25 cm2 of masked active area showed a 98% geometrical FF, 115.09 mA short-circuit current, 3.54 V Voc, 71.09% FF, and 11.58% PCE while exhibiting 8.80% of degradation during a thermal stability test at 100 °C/25% RH and 1 sun light soaking for 1000 h.

18.
ChemSusChem ; 12(1): 224-230, 2019 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-30375174

RESUMEN

A design strategy is proposed for electron-transporting materials (ETMs) with homochiral asymmetric-shaped groups for highly efficient non-fullerene perovskite solar cells (PSCs). The electron transporting N,N'-bis[(R)-1-phenylethyl]naphthalene-1,4,5,8-tetracarboxylic diimide (NDI-PhE) consists of two asymmetric-shaped chiral (R)-1-phenylethyl (PhE) groups that act as solubilizing groups by reducing molecular symmetry and increasing the free volume. NDI-PhE exhibits excellent film-forming ability with high solubility in various organic solvents [about two times higher solubility than the widely used fullerene-based phenyl-C61 -butyric acid methyl ester (PCBM) in o-dichlorobenzene]. NDI-PhE ETM-based inverted PSCs exhibit very high power conversion efficiencies (PCE) of up to 20.5 % with an average PCE of 18.74±0.95 %, which are higher than those of PCBM ETM-based PSCs. The high PCE of NDI-PhE ETM-based PSCs may be attributed to good film-forming abilities and to three-dimensional isotropic electron transporting capabilities. Therefore, introducing homochiral asymmetric-shaped groups onto charge-transporting materials is a good strategy for achieving high device performance.

19.
J Phys Chem Lett ; 9(20): 6024-6031, 2018 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-30259748

RESUMEN

Preserving the stability of Sn-based halide perovskites is a primary concern in developing photovoltaic light-absorbing materials for lead-free perovskite solar cells. Whereas the addition of SnX2 (X = F, Cl, Br) has been demonstrated to improve the photovoltaic performance of Sn halide perovskite solar cells, the mechanistic roles of SnX2 in the performance enhancement have not yet been studied appropriately. Here we perform a comparative study of CsSnI3 films and devices and examine how SnX2 additives affect their stability, and the results are corroborated by first-principles-based theoretical calculations. Unlike the conventional belief that the additives annihilate defects, we find that the additives effectively passivate the surface and stabilize the perovskite phase, promoting the stability of CsSnI3. Our mechanism suggests that SnBr2, which shows ca. 100 h of prolonged stability along with a high power conversion efficiency of 4.3%, is the best additive for enhancing the stability of CsSnI3.

20.
Adv Mater ; : e1801743, 2018 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-30141200

RESUMEN

Readily commercializable and cost-effective next-generation CsPbBr3 perovskite nanocrystals (PNCs) based X-ray detectors are demonstrated. The PNCs-based X-ray detector exhibits higher spatial resolution (9.8 lp mm-1 at modulation transfer function (MTF) = 0.2 and 12.5-8.9 lp mm-1 for a linear line chart), faster response time (≈200 ns), and comparable stability (>40 Gyair s-1 of X-ray exposure) compared with the commercialized terbium-doped gadolinium oxysulfide (GOS)-based detectors (spatial resolution = 6.2 lp mm-1 at MTF = 0.2 and 6.3 lp mm-1 for a linear line chart, response time = ≈1200 ns) because the PNCs-based scintillator has ≈5.6-fold faster average photoluminescence lifetime and stronger emission than the GOS-based one.

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