Showing papers by "Ren-Min Ma published in 2008"

Synthesis of high quality p-type Zn3P2nanowires and their application in MISFETs

Abstract: Single-crystalline Zn3P2nanowires (NWs) have been synthesized on silicon (Si) substrates via a vapor phase transport method. Zn (99.99%) powder and InP (99.99%) fragments were used as the sources, and 10 nm thick thermal evaporated gold (Au) film was used as the catalyst. The as-prepared Zn3P2 NWs have diameters of 100–200 nm and lengths of more than 10 μm. Single NW metal–insulator–semiconductor field-effect transistors (MISFETs) based on Zn3P2 NWs were fabricated. Electrical transport measurements show that the as-grown Zn3P2 NWs are of p-type. The hole concentrations and mobilities of the p-type Zn3P2 NWs are about 5.6 × 1016 cm−3 and 42.5 cm2V−1 s−1, respectively. The on–off ratio of the MISFET is about 4 × 104, and its threshold voltage and transconductance are 2.5 V and 35 nS, respectively. These parameters indicate that the p-type Zn3P2 NWs are of high quality, and may have potential applications in nanoscale electronic and optoelectronic devices.

High-performance nanowire complementary metal-semiconductor inverters

Abstract: We demonstrated the construction of complementary metal-semiconductor (CMES) inverters with single n- and p-type nanowires (NWs) on the same chip. A single p-type NW was assembled by the side of an n-type NW via the electric field assembly method. n- and p-channel metal-semiconductor field-effect transistors were fabricated with n- and p-type NWs, respectively. Based on this, high-performance NW CMES NOT logic gate (inverter) was built. The NW CMES inverters have low operating voltage (≤2 V), high voltage gain (≥7), and low static power dissipation (≤0.3 nW).

Back-gate ZnO nanowire field-effect transistors each with a top Ω shaped Au contact

Abstract: We have fabricated depletion and enhancement modes (D-mode and E-mode) back-gate metal-insulator-semiconductor field-effect-transistors (MISFETs), using two kinds of ZnO nanowires (NWs) labeled as A and B, respectively. The NWs A and B were synthesized via the vapor phase transport method with ZnO∕C admixture and Zn as the sources, respectively. Each of the MISFETs has a top Ω shaped Au contact on the conductive channel. Compared to that without any top Au contact, the on/off ratio (∼106) of the ZnO NW A MISFET increases by a factor of 103, and is the highest one among the back-gate ZnO NW MISFETs ever reported; while the ZnO NW B MISFET changes from D-mode to E-mode when a top Au contact is added. The effects of the Au∕ZnO NW contacts on the performances of the NW A and B MISFETs were discussed.

P−Zn3P2 single nanowire metal-semiconductor field-effect transistors

Abstract: As far as we know, all the single nanowire (NW) metal-semiconductor field-effect transistors (MESFETs) reported are based on n-type NWs. We report MESFETs based on p-type Zn3P2 single NWs in this paper. The p-type Zn3P2 single NW MESFETs operate in the enhancement mode (E-mode). The source-drain current decreases with gate bias (VG) increasing, confirming the p-type conductance of the Zn3P2 NWs. Typically, the p-type Zn3P2 single NW MESFET has an on/off current ratio of 103, a threshold gate voltage of −0.4 V, and a maximum transconductance of 110 nS.