scholarly journals Impact of p-type doping on charge transport in blade-coated small-molecule:polymer blend transistors

2020 ◽  
Vol 8 (43) ◽  
pp. 15368-15376
Author(s):  
Aniruddha Basu ◽  
Muhammad Rizwan Niazi ◽  
Alberto D. Scaccabarozzi ◽  
Hendrik Faber ◽  
Zuping Fei ◽  
...  

Blade-coating is used to fabricate high hole mobility organic transistors based on a p-doped small-molecule:polymer blend semiconductor.

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 939
Author(s):  
Rosario Schiano Lo Moriello ◽  
Davide Ruggiero ◽  
Leopoldo Angrisani ◽  
Enzo Caputo ◽  
Francesco de Pandi ◽  
...  

Thanks to their peculiar features, organic transistors are proving to be a valuable alternative to traditional semiconducting devices in several application fields; however, before releasing their exploitation, simulating their behaviour through adequate circuital models could be advisable during the design stage of electronic circuits and/or boards. Consequently, accurately extracting the parameter value of those models is fundamental to developing useful libraries for hardware design environments. To face the considered problem, the authors present a method based on successive application of Single- and Multi-Objective Evolutionary Algorithm for the optimal tuning of model parameters of organic transistors on thin film (OTFT). In particular, parameters are first roughly estimated to assure the best fit with the experimental transfer characteristics; the estimates are successively refined through the multi-objective strategy by also matching the values of the experimental mobility. The performance of the method has been assessed by estimating the parameters value of both P-type and N-type OTFTs characterized by different values of channel lengths; the obtained results evidence that the proposed method can obtain suitable parameters values for all the considered channel lengths.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1649
Author(s):  
Gemechis D. Degaga ◽  
Sumandeep Kaur ◽  
Ravindra Pandey ◽  
John A. Jaszczak

Vertically stacked, layered van der Waals (vdW) heterostructures offer the possibility to design materials, within a range of chemistries and structures, to possess tailored properties. Inspired by the naturally occurring mineral merelaniite, this paper studies a vdW heterostructure composed of a MoS2 monolayer and a PbS bilayer, using density functional theory. A commensurate 2D heterostructure film and the corresponding 3D periodic bulk structure are compared. The results find such a heterostructure to be stable and possess p-type semiconducting characteristics. Due to the heterostructure’s weak interlayer bonding, its carrier mobility is essentially governed by the constituent layers; the hole mobility is governed by the PbS bilayer, whereas the electron mobility is governed by the MoS2 monolayer. Furthermore, we estimate the hole mobility to be relatively high (~106 cm2V−1s−1), which can be useful for ultra-fast devices at the nanoscale.


Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 338
Author(s):  
Hak Hyeon Lee ◽  
Dong Su Kim ◽  
Ji Hoon Choi ◽  
Young Been Kim ◽  
Sung Hyeon Jung ◽  
...  

An effective strategy for improving the charge transport efficiency of p-type Cu2O photocathodes is the use of counter n-type semiconductors with a proper band alignment, preferably using Al-doped ZnO (AZO). Atomic layer deposition (ALD)-prepared AZO films show an increase in the built-in potential at the Cu2O/AZO interface as well as an excellent conformal coating with a thin thickness on irregular Cu2O. Considering the thin thickness of the AZO overlayers, it is expected that the composition of the Al and the layer stacking sequence in the ALD process will significantly influence the charge transport behavior and the photoelectrochemical (PEC) performance. We designed various stacking orders of AZO overlayers where the stacking layers consisted of Al2O3 (or Al) and ZnO using the atomically controlled ALD process. Al doping in ZnO results in a wide bandgap and does not degrade the absorption efficiency of Cu2O. The best PEC performance was obtained for the sample with an AZO overlayer containing conductive Al layers in the bottom and top regions. The Cu2O/AZO/TiO2/Pt photoelectrode with this overlayer exhibits an open circuit potential of 0.63 V and maintains a high cathodic photocurrent value of approximately −3.2 mA cm−2 at 0 VRHE for over 100 min.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2592 ◽  
Author(s):  
Funeka Matebese ◽  
Raymond Taziwa ◽  
Dorcas Mutukwa

P-type wide bandgap semiconductor materials such as CuI, NiO, Cu2O and CuSCN are currently undergoing intense research as viable alternative hole transport materials (HTMs) to the spiro-OMeTAD in perovskite solar cells (PSCs). Despite 23.3% efficiency of PSCs, there are still a number of issues in addition to the toxicology of Pb such as instability and high-cost of the current HTM that needs to be urgently addressed. To that end, copper thiocyanate (CuSCN) HTMs in addition to robustness have high stability, high hole mobility, and suitable energy levels as compared to spiro-OMeTAD HTM. CuSCN HTM layer use affordable materials, require short synthesis routes, require simple synthetic techniques such as spin-coating and doctor-blading, thus offer a viable way of developing cost-effective PSCs. HTMs play a vital role in PSCs as they can enhance the performance of a device by reducing charge recombination processes. In this review paper, we report on the current progress of CuSCN HTMs that have been reported to date in PSCs. CuSCN HTMs have shown enhanced stability when exposed to weather elements as the solar devices retained their initial efficiency by a greater percentage. The efficiency reported to date is greater than 20% and has a potential of increasing, as well as maintaining thermal stability.


Author(s):  
Jin-Dou Huang ◽  
Jinfeng Zhao ◽  
Kun Yu ◽  
Xiaohua Huang ◽  
Shi-Bo Cheng ◽  
...  

The conducting and optical properties of a series of indeno[1,2-b]fluorene-6,12-dione (IFD)-based molecules have been systematically studied and the influences of butyl, butylthio and dibutylamino substituents on the reorganization energies, intermolecular electronic couplings and charge-injection barriers of IFD have been discussed. The quantum-chemical calculations combined with electron-transfer theory reveal that the incorporation of sulfur-linked side chains decreases reorganization energy associated with hole transfer and optimizes intermolecular π–π stacking, which results in excellent ambipolar charge-transport properties (μh = 1.15 cm2 V−1 s−1 and μe = 0.08 cm2 V−1 s−1); in comparison, addition of dibutylamino side chains increases intermolecular steric interactions and hinders perfect intermolecular π–π stacking, which results in the weak electronic couplings and finally causes the low intrinsic hole mobility (μh = 0.01 cm2 V−1 s−1). Furthermore, electronic spectra of butyl-IFD, butylthio-IFD and dibutylamino-IFD were simulated and compared with the reported experimental data. Calculations demonstrate that IFD-based molecules possess potential for developing novel infrared and near-infrared probe materials via suitable chemical modifications.


2002 ◽  
Vol 268 (1) ◽  
pp. 215-220
Author(s):  
Th. Hölbling ◽  
R. Waser

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5339
Author(s):  
Lian Zhang ◽  
Rong Wang ◽  
Zhe Liu ◽  
Zhe Cheng ◽  
Xiaodong Tong ◽  
...  

This work studied the regulation of hole concentration and mobility in p-InGaN layers grown by metalorganic chemical vapor deposition (MOCVD) under an N-rich environment. By adjusting the growth temperature, the hole concentration can be controlled between 6 × 1017/cm3 and 3 × 1019/cm3 with adjustable hole mobility from 3 to 16 cm2/V.s. These p-InGaN layers can meet different requirements of devices for hole concentration and mobility. First-principles defect calculations indicate that the p-type doping of InGaN at the N-rich limiting condition mainly originated from Mg substituting In (MgIn). In contrast with the compensation of nitrogen vacancy in p-type InGaN grown in a Ga-rich environment, the holes in p-type InGaN grown in an N-rich environment were mainly compensated by interstitial Mg (Mgi), which has very low formation energy.


2018 ◽  
Vol 245 ◽  
pp. 96-101 ◽  
Author(s):  
Krishna Deb ◽  
Kamanashis Sarkar ◽  
Arun Bera ◽  
Ajit Debnath ◽  
Biswajit Saha

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1091
Author(s):  
Minjong Lee ◽  
Joohoon Kang ◽  
Young Tack Lee

In this paper, we propose a solvent-free device fabrication method using a melt-blown (MB) fiber to minimize potential chemical and thermal damages to transition-metal-dichalcogenides (TMDCs)-based semiconductor channel. The fabrication process is composed of three steps; (1) MB fibers alignment as a shadow mask, (2) metal deposition, and (3) lifting-up MB fibers. The resulting WSe2-based p-type metal-oxide-semiconductor (PMOS) device shows an ON/OFF current ratio of ~2 × 105 (ON current of ~−40 µA) and a remarkable linear hole mobility of ~205 cm2/V·s at a drain voltage of −0.1 V. These results can be a strong evidence supporting that this MB fiber-assisted device fabrication can effectively suppress materials damage by minimizing chemical and thermal exposures. Followed by an MoS2-based n-type MOS (NMOS) device demonstration, a complementary MOS (CMOS) inverter circuit application was successfully implemented, consisted of an MoS2 NMOS and a WSe2 PMOS as a load and a driver transistor, respectively. This MB fiber-based device fabrication can be a promising method for future electronics based on chemically reactive or thermally vulnerable materials.


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