Seminar

Date 2021-11-23 
Time 16:00 
Title Overcoming Limitation of Next Generation Semiconductor Materials and Devices using Interface Engineering 

■ 제 목:  Overcoming Limitation of Next Generation Semiconductor Materials and Devices using Interface Engineering

 

 연 사:  임경근 박사 (한국표준과학연구원)             

 

■ 일 시:  2021년 11월 23(화) 오후 4시 

 

■ Host :  조힘찬 교수 

 

■ 참가자 접속정보 (3:50분까지 참가를 부탁드립니다)   

      접속 링크: https://kaist.zoom.us/j/8080757553 

      ID: 808 075 7553

      비밀번호: 2021mse

 

 Abstract :  

The interfacial materials has played the key role in efficient charge extraction in flexible semiconductor devices, but the mechanisms at the interface and of the resulting effects on applications have not been well established. 
 
In organic photovoltaics (OPVs) and organic-inorganic hybrid perovskite solar cell (PSCs), the mechanisms of decoupled interface dipole moments are evaluated by using spontaneously and nonspontaneously aligned dipolar interface molecules, thereby the energy-level adjustment of the dipolar interface layer in the devices are elucidated. We systematically tailored the interface dipole moment and the energy level alignment of interface materials to remove the energy offset at the interface and achieve the efficient organic solar cells and hybrid perovskite solar cells with diverse interface materials and photoactive materials.
 
The current record for high-speed organic transistors is held by the vertical organic thin film transistor (VOTFT) due to very short vertical carrier paths and simple device structures for commercialization. Electrochemically anodized aluminum oxide is used in vertical organic permeable base transistor (vertical OPBT) and vertical organic field-effect transistor (VOFET) for excellent dielectric structures and interface modifications. For the first time we show the successful enhancement of vertical OPBT with the electrochemically-oxidized base electrode by anodization. Leakage currents and parasitic capacitances are significantly reduced, paving the way to even the highest transit frequencies amongst the reported organic transistors. For the vertical OFET, we use electrochemically-oxidized insulating layer to form the charge blocking layer at the vertically-stacked source-drain interface. Therefore VOTFTs with low leakage current, high on/off current ratio, high-speed, and low operating voltage are demonstrated with the electrochemically anodized electrodes.