Trap states and transport characteristics in picene thin film field-effect transistor

Abstract

Transport characteristics and trap states are investigated in picene thin film field-effect transistor under O2 atmosphere on the basis of multiple shallow trap and release (MTR) model. The channel transport is dominated by MTR below 300 K. It has been clarified on the basis of MTR model that the O2-exposure induces a drastic reduction in shallow trap density to increase both the field-effect mobility μ and on-off ratio. We also found that the O2-exposure never caused an increase in hole carrier density. Actually, a very high μ value of 3.2 cm2 V−1 s−1 is realized under 500 Torr of O2.

Accessing Surface Brillouin Zone and Band Structure of Picene Single Crystals

“…In the tight-binding approximation, the effective mass of the hole m h * can be given by m h * = 2 /2tb 2 , while our results gives m h * = 2.24 m 0 (m 0 : the free electron mass). In a broad band model (W > k B T ), the hole mobility µ h can be estimated as µ h ≥ 20 (m 0 /m * ) × (300/T ) [22], so that the lower limit of µ h is 9.0 cm 2 /Vs at 298 K. This value is comparable to the largest µ h (∼5 cm 2 /Vs) of reported picene thin film transistors [7,8], and suggests that the hole mobility in the thin films is dominated by the band transport [7,8,14,23].…”

The Position of Nitrogen in N‐Heteropentacenes Matters

“…The resulting holes can fi ll into trap states, leading to higher effective fi eld-effect mobility. [ 20 ] …”

Electronic structure of pristine and K-doped solid picene: Nonrigid band change and its implication for electron-intramolecular-vibration interaction

“…7͒ and high carrier mobility of greater than 3 cm 2 V −1 s −1 by exposure to O 2 . 8 However, neither the electronic structure of the pristine nor doped picene has been reported, yet. It is, therefore, crucial to study experimental electronic structure of pristine picene and its evolution with doping in order to understand the mechanism of superconductivity.…”