Ambipolar field-effect transistor based on organic-inorganic hybrid structure

Abstract

The authors developed an ambipolar field-effect transistor (FET) based on an organic-inorganic hybrid structure that consisted of an indium zinc oxide and pentacene double layer fabricated on a SiO2∕n++-Si substrate. Although the FETs based on an indium zinc oxide or pentacene single layer only showed unipolar FET characteristics, the hybrid FET showed definite ambipolar FET characteristics. The authors obtained a highly saturated field-effect hole and electron mobilities of 0.14 and 13.8cm2∕Vs. Furthermore, the authors demonstrated electroluminescence from hybrid FETs using tetracene as an emitting layer. The authors’ success shows that the hybridization of organic and inorganic materials opens up a new field in electronics.

Solution‐Deposited Zinc Oxide and Zinc Oxide/Pentacene Bilayer Transistors: High Mobility n‐Channel, Ambipolar, and Nonvolatile Devices

“…5b), because ZnO has its ''LUMO'' level at 4.4 eV (much closer to the gold work function of 5.1 eV than a typical organic semiconductor LUMO) and p-pentacene has its HOMO level at 5.0 eV. Very recently one group reported a similar organic-inorganic bilayer ambipolar transistor where the n-material was a mixed vapor-deposited oxide, [55] although in their result n-type mobility was many times higher than p-type mobility. For application of ambipolar FETs, balanced electron and hole polarity is preferred.…”

Control of Ambipolar Transport in SnO Thin-Film Transistors by Back-Channel Surface Passivation for High Performance Complementary-like Inverters

“…So far, the oxide-based complementary circuits are mainly combined with p-type organic or carbon-based TFTs. [5][6][7][8] However, the incompatibility for processing diverse active materials makes the circuit design and integration more complicated and unacceptable for practical applications. Therefore, it is imperative to excavate the cache of p-type or bipolar oxide semiconductors to allow fabrication more compact CMOS devices.…”

High mobility solution-processed hybrid light emitting transistors

“…12 Despite the interesting demonstration of the LEFET concept, to date, the absolute amount of light emitted from LEFETs has generally been low compared to OLED devices. While the mobility of polycrystalline silicon used in commercial OLED display back panels is on the order of 100-150 cm 2 /V s, the mobilities of LEFETs based on organic transport materials tend to be less than $1 cm 2 /V s. In the case of the solution processed metal oxide transport layers 12 the mobilities have been at best $5 cm 2 /V s; and for sputtered metal oxide transport layer 13 the mobilities have reached around 14 cm 2 /V s. These mobilities lead to smaller currents through the LEFETs compared to OLEDs on silicon backplanes, which makes it difficult to achieve bright light emission from the emissive layer.…”

“…Nevertheless, in spite of this these combined EQE and brightness exceed those reported to date for hybrid light emitting transistors. 12,13 Taking these observations into account, the mechanism for operation of these hybrid LEFETs involves injection of electrons from the Ag source electrode into the conduction band of the CdS (4.3 eV), 14 transport of electrons along the CdS/ dielectric interface, injection of electrons from the conduction band of CdS into the LUMO of SY (2.9 eV) where they subsequently recombine with holes injected from the MoO x /Au drain electrode into the HOMO of SY (5.3 eV; measured by PESA). 12 Under these circumstances, carrier recombination occurs within the SY layer near the positively biased drain electrode, leading to light emission as illustrated in Fig.…”