Hao-Di Wu

Preparation and ambipolar transistor characteristics of co-crystal microrods of dibenzotetrathiafulvalene and tetracyanoquinodimethane

Co-crystal microrods of dibenzotetrathiafulvalene (DBTTF) and tetracyanoquinodimethane (TCNQ) molecules with the mixed-stack structure were prepared via a facile solution process and fully characterized. The as-prepared microrods were directly used for fabricating prototype devices, which exhibited typical ambipolar charge transport characteristics. The result indicated that the co-crystal microrods of DBTTF-TCNQ were potentially useful for miniaturized devices.

One-step fabrication of an ultralong zinc octaethylporphyrin nanowire network with high-performance photoresponse

An interconnected network of ultralong zinc octaethylporphyrin (ZnOEP) nanowires was fabricated via a solution process and directly used for constructing prototype photodetectors. The device exhibited high reproducibility and sensitivity with the largest photoswitching ratio over 104. The facile fabrication process and the superior performance made ZnOEP an ideal candidate for photodetector applications.

Metal Ions Mediated Morphology and Phase Transformation of Chalcogenide Semiconductor: From CuClSe2 Microribbon to CuSe Nanosheet

Foreign ions are of significant importance in controlling and modulating the morphology of semiconductor nanocrystals during the colloidal synthesis process. Herein, we demonstrate the potential of foreign metal ions to simultaneously control the morphology and crystal phase of chalcogenide semiconductors. The results indicate that the introduction of Al(3+) ions can induce the structural transformation from monoclinic CuClSe2 microribbons (MRs) to klockmannite CuSe nanosheets (NSs) and the growth of large-sized CuSe NSs. The as-prepared micrometer-sized CuSe NSs exhibit a high-conducting behavior, long-term durability, and environment stability. The novel properties enable CuSe NSs to open up a bright prospect for printable electrical interconnects and flexible electronic devices.

Precise growth of low-dimensional pyrene·perylene·TCNQ co-crystals and structure–property related optoelectronic properties

A phase-transformation method has been developed for the precise growth of charge-transfer (CT) co-crystals with varied stoichiometries. Perylene·TCNQ (P1T1) microrods, pyrene·perylene·TCNQ (PyPeT) microrods and (perylene)3·TCNQ (P3T1) microsheets were successfully constructed. The phase transformation can not only happen from P1T1 or P3T to PyPeT, but also from P3T1 to P1T1, which can be controlled by changing the solute concentration. Due to the additional pyrene in PyPeT compared to P1T1, devices based on PyPeT microrods show slightly lower electron mobility and much larger positive threshold than P1T1 microrods. In addition, both of them can be used as phototransistors with a maximum Ion/Ioff ratio of ca. 1000.

Preparation of nano/microstructures of CuOEP–TCNQ cocrystals with controlled stacking and their photoresponse properties

Nano/microstructures of copper octaethylporphyrin (CuOEP, donor)–tetracyanoquinodimethane (TCNQ, acceptor) cocrystals with controlled stacking were prepared by a facile solution method and fully characterized. The as-prepared CuOEP–TCNQ cocrystals were either nanoribbons of TCNQ·2CuOEP or microrods of TCNQ·CuOEP, which had DDA(DDA)nDDA and DA(DA)nDA stacking, respectively. For the first time, a phase transformation was found to occur from nanoribbons of TCNQ·2CuOEP to microrods of TCNQ·CuOEP, which was mainly controlled by the concentration of TCNQ. Moreover, prototype devices were fabricated to investigate their photoresponse properties. The results demonstrated that the DDA(DDA)nDDA stacking had much better photoresponse than the DA(DA)nDA stacking.

Shape-controlled synthesis of platinum octaethylporphyrin crystalline aggregates modulated by versatile ionic liquids

This work presents a facile approach toward the synthesis of platinum octaethylporphyrin crystalline aggregates with wires, leaves, plates, and four-leaf clover like architectures by exploitation of intriguing ionic liquid-mediated solution self-assembly. Moreover, the well-defined microwires exhibit highly reproducible and sensitive photo-response characteristics.

Facile fabrication of aligned arrays of ultralong CoOEP nanowires for high-performance optoelectronic devices

Aligned arrays of ultralong CoOEP nanowires were fabricated by a facile solution process. The prototype devices based on the as-obtained ordered array showed excellent optoelectronics performance with an on-to-off current ratio of 1.7???104 and an average mobility of 1.4???10?3 cm2 V?1 s?1 in the dark. Moreover, the ordered array of CoOEP nanowires exhibited highly photosensitive field-effect transistor characteristics, which had a photoresponsivity of 3.5 mA W?1 and a photo-current/dark-current ratio of 4.3???103 at low gate voltage of 6.5 V. The facile fabrication and good photoresponse makes the CoOEP nanowire arrays promising in optoelectronic applications.

Efficient non-halogenated solvent for the template-free solution synthesis of ultralong copper octaethylporphyrin nanowire networks with strong photoswitching properties

Rationally solution-processed organic electronics are expected to pave the way for low-cost and large-area devices with new and exciting applications. In this study, a non-halogenated solvent was employed for the first time for the one-step and scalable synthesis of extremely high aspect ratio organic semiconducting nanowires of copper octaethylporphyrin (CuOEP) using a cast assembly method under a solvent atmosphere. Remarkably, these single crystalline nanowires exhibited excellent photoswitching effects with reliable reproducibility and superior stability, indicating their potential for application in high-performance optoelectronic devices.

Facile fabrication and excellent electrical conductivity of ultralong nanobelt film of butoxy-substituted copper phthalocyanines

Well-defined single-crystalline nanobelts of butoxy-substituted copper phthalocyanine (CuPcOC4) have been rapidly prepared by a facile and reliable non-solvent nucleation method without any template. Remarkably, the nanobelt film exhibited an excellent electrical conductivity of up to 5.2 S m−1, which is one of the highest values reported for organic semiconducting materials.

Novel CuClSe2 microribbons: microwave-assisted synthesis, phase transformation and photo-response properties

A microwave-assisted method was developed to synthesize novel single-crystalline CuClSe2 microribbons (MRs) in high yield. Their phase transformation and stability to thermal irradiation were systematically studied. The single CuClSe2 MR-based device showed a favorable photosensitivity and long-term environmental stability. This implies good prospects for CuClSe2 MRs in low-cost and high-performance photodetectors for practical use.