Hybrid Organic-inorganic Semiconductors Research Articles

Design, synthesis, structure analysis and photophysical characterization of robust and solution-processable one-dimensional copper(I) iodide-based inorganic-organic hybrid semiconductors

A series of new one-dimensional (1D) CuI-based inorganic-organic hybrid semiconductors have been designed and synthesized, namely, 1D-(dmpi)3Cu6I9 (1), 1D-(5asn)2Cu4I6 (2), 1D-(Nhex)2Cu4I6 (3) and 1D-(Npipz)2Cu2I6 (4) (dmpi = N,N-dimethylpiperidinium, 5asn = 5-azaspiro[4.4]nonan-5-ium, Nhex = cyclohexanaminium, Npipz = 1-methylpiperazine-1,4-diium). All structures are composed of ionically bonded aliphatic cations and various 1D CuI anionic copper iodide chains. Due to their wide bandgaps, all materials display ultraviolet (UV) emission between 340 and 390 nm, with internal quantum yields (IQYs) up to 6.4 %. All compounds are solution-processable due to their ionic bonding nature and have excellent thermal stability with their decomposition temperature (Td) up to 260 °C, as well as impressive air stability over long time periods. Due to the use of aliphatic cations as structure directing agents, the photophysical properties of these materials are dominated by their inorganic components, as confirmed by electronic structure calculations employing density functional theory (DFT). Additionally, their non-toxicity and facile synthesis suggest that this type of material is promising for practical use. These findings provide helpful insight into the future development of high-performance wide bandgap semiconductors that may be potentially useful in various UV-emitting or other optoelectronic applications.

Excitonic cuprophilic interactions in one-dimensional hybrid organic–inorganic crystals

A copper based organic–inorganic hybrid perovskite-like system (TMA) Cu2Br3 is synthesized which exhibits impressive photoconductivity properties due to the emergence of excitonic cuprophilic interactions.

Modification of Graphite/SiO2 Film Electrodes with Hybrid Organic–Inorganic Perovskites for the Detection of Vasoconstrictor Bisartan 4-Butyl-Ν,Ν-bis{[2-(2H-tetrazol-5-yl)biphenyl-4-yl]methyl}imidazolium Bromide

In the present work, a hybrid organic–inorganic semiconductor (HOIS) has been used to modify the surface of a graphite paste/silica (G–SiO2) film electrode on a conducting glass substrate to fabricate a promising, sensitive voltammetric sensor for the vasoconstrictor bisartan BV6, which could possibly treat hypertension and COVID-19. The HOIS exhibits exceptional optoelectronic properties with promising applications not only in light-emitting diodes, lasers, or photovoltaics but also for the development of voltammetric sensors due to the ability of the immobilized HOIS lattice to interact with ions. This study involves the synthesis and characterization of an HOIS and its attachment on the surface of a G–SiO2 film electrode in order to develop a nanocomposite, simple, sensitive with a fast-response, low-cost voltammetric sensor for BV6. The modified HOIS electrode was characterized using X-ray diffraction, scanning electron microscopy, and optical and photoluminescence spectroscopy, and its electrochemical behavior was examined using cyclic voltammetry. Under optimal conditions, the modified G–SiO2 film electrode exhibited a higher electrocatalytic activity towards the oxidation of BV6 compared to a bare graphite paste electrode. The results showed that the peak current was proportional to BV6 concentration with a linear response range from 0 to 65 × 10−6 (coefficient of determination, 0.9767) and with a low detection limit of 1.5 × 10−6 M (S/N = 3), estimated based on the area under a voltammogram, while it was 3.5 × 10−6 for peak-based analysis. The sensor demonstrated good stability and reproducibility and was found to be appropriate for the determination of drug compounds such as BV6.

Real-Time Monitoring of Progressive Crystal Phase Transformations and Associated Multi-Phase Optical Exciton Dynamics in Mixed (2D/3D) Inorganic–Organic Hybrid Semiconductors

Real-Time Monitoring of Progressive Crystal Phase Transformations and Associated Multi-Phase Optical Exciton Dynamics in Mixed (2D/3D) Inorganic–Organic Hybrid Semiconductors

1D Hybrid Semiconductor Silver 2,6-Difluorophenylselenolate.

Organic-inorganic hybrid materials present new opportunities for creating low-dimensional structures with unique light-matter interaction. In this work, we report a chemically robust yellow emissive one-dimensional (1D) semiconductor, silver 2,6-difluorophenylselenolate─AgSePhF2(2,6), a new member of the broader class of hybrid low-dimensional semiconductors, metal-organic chalcogenolates. While silver phenylselenolate (AgSePh) crystallizes as a two-dimensional (2D) van der Waals semiconductor, introduction of fluorine atoms at the (2,6) position of the phenyl ring induces a structural transition from 2D sheets to 1D chains. Density functional theory calculations reveal that AgSePhF2 (2,6) has strongly dispersive conduction and valence bands along the 1D crystal axis. Visible photoluminescence centered around λp ≈ 570 nm at room temperature exhibits both prompt (110 ps) and delayed (36 ns) components. The absorption spectrum exhibits excitonic resonances characteristic of low-dimensional hybrid semiconductors, with an exciton binding energy of approximately 170 meV as determined by temperature-dependent photoluminescence. The discovery of an emissive 1D silver organoselenolate highlights the structural and compositional richness of the chalcogenolate material family and provides new insights for molecular engineering of low-dimensional hybrid organic-inorganic semiconductors.

Effect of Pd(II) uptake on high-temperature phase transitions in a hybrid organic-inorganic perovskite semiconductor.

Hybrid organic-inorganic perovskites (HOIPs) have been widely studied for their interesting functions and potential applications. Here, we report a novel sulfur-containing hybrid organic-inorganic perovskite based on a one-dimensional ABX3-type compound: [C3H7N2S]PbI3 ([C3H7N2S]+ is 2-amino-2-thiazolinium) (1). Compound 1 undergoes two high-temperature phase transitions at 363 K and 401 K, respectively, showing a band gap of 2.33 eV, and has a narrower band gap compared to other one-dimensional materials. Moreover, by introducing thioether groups into the organic component, 1 has the ability to uptake Pd(II) ions. Compared with previously reported low-temperature isostructural phase transition sulfur-containing hybrids, the molecular motion of 1 becomes more intense under the stimulation of high temperature, leading to changes in the space group during the two phase transitions (Pbca → Pmcn → Cmcm), which are no longer the previous isostructural phase transitions. Significant changes in the phase transition behavior and semiconductor properties before and after metal absorption make it possible to monitor the absorption process of metal ions. The study of the effect of Pd(II) uptake on phase transitions may be helpful to reveal the mechanism of phase transitions more deeply. This work will broaden the hybrid organic-inorganic ABX3-type semiconductor family and pave the way for the development of organic-inorganic hybrid-based multifunctional phase transition materials.

Linear and nonlinear optical excitons in primary cyclic ammonium based inorganic–organic hybrid semiconductor series

The low dimensional inorganic–organic (IO) hybrid semiconductors become a fascinating subject of interest due to their unique crystal structural packing and tunable optical exciton emission features. These naturally self-assembled 2D IO hybrid semiconductors form multiple quantum wells (MQWs) like structure due to the quantum widths of both organic moiety and inorganic network , enabling them to show stable room temperature Mott-type excitons with large exciton binding energy. A systematic co-existence of two kinds of excitons observable from one-(ħω ≥ Eg) and two-photon (2ħω ≥ Eg) excitations is studied to probe into deeper details of sensitive structural changes in the IO-hybrids thin film and single crystals.

Highly soluble copper(i) iodide-based hybrid luminescent semiconductors containing molecular and one-dimensional coordinated anionic inorganic motifs

A series of all-in-one (AIO) type copper halide based luminescent inorganic-organic hybrid semiconductors have been synthesized and characterized. The study offers insights into the structure-property relationships in this material family.

Room-Temperature Spin Transport in Metal Nanocluster-Based Spin Valves.

As a new type of inorganic-organic hybrid semiconductor, quantum-confined atomically precise metal nanoclusters (MNCs) have been widely applied in the fields of chemical sensing, optical imaging, biomedicine and catalysis. Herein, we successfully design and fabricate the first example of MNC-based spin valves (SVs) that exhibit remarkable magnetoresistance (MR) value up to 1.6 % even at room temperature (300 K). The concomitant photoresponse of MNC-based SVs unambiguously confirms that the spin-polarized electron transmission takes place across the MNC interlayer. Furthermore, the spin-dependent transport property of MNC-based SVs is largely varied by changing the atomic structure of MNCs. Both experimental proofs and quantum chemistry calculations reveal that the atomic structure-discriminative spin transport behavior is attributed to the distinct spin-orbit coupling (SOC) effect of MNCs.

Modelling tandem/multi-junction hybrid perovskite–organic solar cells: A combined drift–diffusion and kinetic Monte Carlo study

Hybrid Organic–inorganic semiconductors are an excellent option for developing photovoltaic devices because of their broad range of bandgaps, inexpensive deposition techniques, and broad solar spectrum absorption. Perovskite–organic tandem solar cells with two terminals (2T) have emerged as the potential architectures to reach high efficiency. Several device characteristics like thickness and bandgaps of the sub-cells must be optimized to maximize solar spectrum utilization in a 2T tandem cell. This study proposes a multiscale simulation model for tandem/multi-junction architecture using hybrid perovskite–organic solar cells. Initially, tandem architecture using perovskite absorbers and organic blend is modelled to explore the series-connected tandem solar cell structure and analyse the effect on the device performance. We observe that the implemented perovskite–organic tandem architecture can achieve high efficiency of 19.8%. This work further explores different perovskite cells combined with the organic blend in a multi-junction configuration to cover the broad solar spectrum with as high as 25.2% power conversion efficiency. In turn, this gives a concrete model representation that can help optimize the device architecture leading to high-efficiency hybrid perovskite–organic devices.

Solution-processable copper(I) iodide-based inorganic-organic hybrid semiconductors composed of both coordinate and ionic bonds

Three new one-dimensional (1D) All-In-One (AIO) type CuI-based hybrid semiconductors with both dative and ionic bonds between the inorganic and organic components have been successfully designed and synthesized by using the ligands containing both cationic center and coordination available sites. Structural analysis confirms that all compounds share the same formula of Cu4I6(L)2 (L ​= ​ligand) and are composed of 1D-Cu4I62− anionic chains that coordinate to cationic ligands. These materials demonstrate high stability towards heat and moisture and excellent solution processability due to their unique bonding nature. They emit low energy light ranging from green to orange color (530–590 ​nm). The origin and mechanism of their emissions were studied by both experimental and theoretical methods. More importantly, all compounds can be easily fabricated into films by solution process, a desired but rare feature for most of CuI-based hybrids built of extended networks.

Time-resolved vibrational-pump visible-probe spectroscopy for thermal conductivity measurement of metal-halide perovskites.

Understanding thermal transport at the microscale to the nanoscale is crucially important for a wide range of technologies ranging from device thermal management and protection systems to thermal-energy regulation and harvesting. In the past decades, non-contact optical methods, such as time-domain and frequency-domain thermoreflectance, have emerged as extremely powerful and versatile thermal metrological techniques for the measurement of material thermal conductivities. Here, we report the measurement of thermal conductivity of thin films of CH3NH3PbI3 (MAPbI3), a prototypical metal-halide perovskite, by developing a time-resolved optical technique called vibrational-pump visible-probe (VPVP) spectroscopy. The VPVP technique relies on the direct thermal excitation of MAPbI3 by femtosecond mid-infrared optical pump pulses that are wavelength-tuned to a vibrational mode of the material, after which the time dependent optical transmittance across the visible range is probed in the ns to the μs time window using a broadband pulsed laser. Using the VPVP method, we determine the thermal conductivities of MAPbI3 thin films deposited on different substrates. The transducer-free VPVP method reported here is expected to permit spectrally resolving and spatiotemporally imaging of the dynamic lattice temperature variations in organic, polymeric, and hybrid organic-inorganic semiconductors.

Femtosecond optical nonlinearities and ultrafast absorption dynamics of colloidal 2D organometal halide ((C12H25–NH3)2PbI4) nanoparticles and thin films

Layered 2D Inorganic-Organic (IO) hybrid semiconductors of the type (R–NH3)2PbI4 have shown tremendous potential applications in various photonics and optoelectronic devices. In this work, femtosecond laser induced optical nonlinearities and excited state charge carrier dynamics of organometal halide (C12H25–NH3)2PbI4 (C12PI) 2D colloidal nanoparticles (NPs) and the thin film counterpart are investigated. These colloidal 2D NPs of sizes ∼9 nm, show third-order optical nonlinearity having two-photon absorption coefficient (2PA) (β∼26-23 cm/GW) and positive nonlinear refractive index (n2∼7.6 × 10−2 cm2/GW), while thin films show β∼78–134 cm/GW and n2∼0.003-0.2 × 10−2 cm2/GW. The origins of two-photon induced absorption and Kerr-type refractive nonlinearity are as a result of induced molecular polarization and charge transfer effects between organic cation (C12H25–NH3)+ and inorganic anion (PbI6 octahedra). The ultrafast transient absorption spectral studies demonstrate the room-temperature Mott-type exciton excited-state charge carrier dynamics and charge carrier recombination features. The laser pump intensity dependent transient absorption spectral (TAS) features reveal wide information about ground state bleaching (GSB∼510 nm, ΔA<0 with decay of 28.2–3.2 ps) along with a photo-induced absorption (PIA∼476 nm, ΔA>0, with decay of 22–6.3 ps) regions. The systematic studies of optical nonlinearities and ultrafast absorption dynamics of 2D IO hybrid semiconductor colloidal nanoparticles and thin film will provide a new platform for advanced photonics and ultrafast optical switching devices applications.

Size and Quality Enhancement of 2D Semiconducting Metal-Organic Chalcogenolates by Amine Addition.

The use of two-dimensional (2D) materials in next-generation technologies is often limited by small lateral size and/or crystal defects. Here, we introduce a simple chemical strategy to improve the size and overall quality of 2D metal-organic chalcogenolates (MOCs), a new class of hybrid organic-inorganic 2D semiconductors that can exhibit in-plane anisotropy and blue luminescence. By inducing the formation of silver-amine complexes during a solution growth method, we increase the average size of silver phenylselenolate (AgSePh) microcrystals from <5 μm to >1 mm, while simultaneously extending the photoluminescence lifetime and suppressing mid-gap emission. Mechanistic studies using 77Se NMR suggest dual roles for the amine in promoting the formation of a key reactive intermediate and slowing down the final conversion to AgSePh. Finally, we show that amine addition is generalizable to the synthesis of other 2D MOCs, as demonstrated by the growth of single crystals of silver 4-methylphenylselenolate (AgSePhMe), a novel member of the 2D MOC family.

MaPBI3 and 2D hybrid organic-inorganic perovskite based microcavities employing periodic, aperiodic, and disordered photonic structures with light-induced tuning possibility

Inorganic-organic perovskites semiconductors are becoming increasingly interesting due to their remarkable optical properties, such as a high photoluminescence quantum yield and the possibility to show optical gain in a broad range of wavelengths. We have here simulated microcavities that embed MaPBI3 and 2D hybrid organic-inorganic perovskite semiconductors by sandwiching such active layers between periodic, aperiodic and disordered photonic structures. The complex refractive index dispersions of MaPBI3 and 2D hybrid organic-inorganic perovskite have been recently reported in literature. Thus, we have carefully considered the refractive index dispersion of all the materials employed, such as silicon dioxide, titanium dioxide, and the aforementioned perovskite layers. Moreover, by employing a photochromatic polymer, namely the diarylethene-based polyester pDTE, we have designed a microcavity with light-induced tuning of the cavity modes is possible.

Synthesis, characterization and optoelectronic properties of 2D hybrid RPbX4 semiconductors based on an isomer mixture of hexanediamine-based dications

Abstract Three new hybrid two-dimensional (2D) organic–inorganic semiconductors are presented, which contain lead halides and a mixture of hexanediamine-based isomers in the stoichiometry [2,2,4(2,4,4)-trimethyl-1,6-hexanediamine]PbX4 (X = I, Br, Cl). These hexanediamine derivatives, with attached methyl groups at the carbon backbone of both isomers, determine the packing of the organic layers between the inorganic 2D sheets, while the optical absorption and photoluminescence spectra reveal excitonic peaks at T = 77 K and room temperature. The as-synthesized semiconductors were stored for three years in the dark and under low humidity and were examined again and the results were compared to those of the fresh materials. The chloride analogue, after the three year storage, displays white-like luminescence. The use of non-equivalent isomer and racemic mixtures in the organic component to form hybrid organic–inorganic semiconductors is an efficient method to alter the properties of 2D perovskites by tuning the isomers’ chemical functionalities. Finally, a comparison of the observed excitonic absorption and photoluminescence signals to that of analogous 2D compounds is discussed.

Two-Dimensional Copper Iodide-Based Inorganic–Organic Hybrid Semiconductors: Synthesis, Structures, and Optical and Transport Properties

A group of copper iodide-based hybrid semiconductors with the general formula of 2D-CuI(L)0.5 (L = organic ligands) are synthesized and structurally characterized. All compounds are two-dimensional (2D) networks made of one-dimensional (1D) copper iodide staircase chains that are interconnected by bidentate nitrogen-containing ligands. Results from optical absorption and emission experiments and density functional theory (DFT) calculations reveal that their photoluminescence (PL) can be systematically tuned by adjusting the lowest unoccupied molecular orbital (LUMO) energies of the organic ligands. Charge carrier transport measurements were carried out for the first time on single crystals of selected 2D-CuI(L)0.5 structures, and the results show that they possess p-type conductivity with a Hall mobility of ∼1 cm2 V–1 s–1 for 2D-CuI(pm)0.5 and 0.13 cm2 V–1 s–1 for 2D-CuI(pz)0.5, respectively. These values are comparable to or higher than the mobilities of typical highly luminescent organic semiconductors. This work suggests that robust, high-dimensional copper iodide hybrid semiconductors are promising candidates to be considered as a new type of emissive layer for light-emitting diode (LED) devices.

Study of Surface and Bulk Recombination Kinetics of Two-Dimensional Inorganic–Organic Hybrid Semiconductors under Linear and Nonlinear Femtosecond Transient Absorption Analysis

Study of Surface and Bulk Recombination Kinetics of Two-Dimensional Inorganic–Organic Hybrid Semiconductors under Linear and Nonlinear Femtosecond Transient Absorption Analysis

Alternative fabrication methodologies for two-dimensional self-assembled Inorganic-Organic hybrid semiconductors

This report presents the structural and optical properties of(R-NH 3 ) 2 PbI 4 type Inorganic-Organic (IO) hybrids, prepared from alternative fabrication techniques, without any excess usage of Iodine. The fabrication relies on common deposition techniques viz., thermal vacuum deposition, electrochemical deposition, and spincoating. The resulting two-dimensional (2D) structures are alternatively stacked-up along c-axis by inorganic (PbI 6 extended network) layers with organic (R–NH 3 ) - moieties as spacers. These hybrids show strong room-temperature exciton features confined within the lowest inorganic bandgap. The proposed methodologies are simple alternatives to the conventional multi-step fabrication methodologies and are directly applicable to varieties of IO hybrids of different dimensionalities for various optoelectronic applications. • Novel methodologies for IO hybrids without metal halide and excess of halide usage. • Efficient direct conversion of pure Pb metal films into perfect layered 2D IO hybrids. • Nano and microcrystal fabrication from lead acetate based electrodeposition. • Strong room-temperature exciton photoluminescence from IO hybrids is demonstrated.

Pentacene and tetracene molecules and films on H/Si(111): level alignment from hybrid density functional theory

The electronic properties of hybrid organic–inorganic semiconductor interfaces depend strongly on the alignment of the electronic carrier levels in the organic/inorganic components. In the present work, we address this energy level alignment from first principles theory for two paradigmatic organic–inorganic semiconductor interfaces, the singlet fission materials tetracene and pentacene on H/Si(111), using all-electron density functional theory calculations with a hybrid exchange–correlation functional. For isolated tetracene on H/Si(111), a type I-like heterojunction (lowest-energy electron and hole states on Si) is found. For isolated pentacene, the molecular and semiconductor valence band edges are degenerate. For monolayer films, we show how to construct supercell geometries with up to 1192 atoms, which minimize the strain between the inorganic surface and an organic monolayer film. Based on these models, we predict the formation of type II heterojunctions (electron states on Si, hole-like states on the organic species) for both acenes, indicating that charge separation at the interface between the organic and inorganic components is favored. The paper discusses the steps needed to find appropriate low-energy interface geometries for weakly bonded organic molecules and films on inorganic substrates from first principles, a necessary prerequisite for any computational level alignment prediction.