Research

Research Keyntoe: Strained Si/Ge FETs, Si/Ge on glass, insulator, and flexible substrate, solar cell ( laser doping, HIT, micromorph, triple junction, CIGS), group IV photonics (emitters and detectors), SiGe(C, Sn) material and device,  Prof. Liu invented the MIS structures for LEDs and detectors. He grew the strained Si with a record high mobility of 2x106 cm2/Vs. He publishes ~150 international SCI journal papers, and160+ conference papers (including 10 IEDM papers and 12 invited papers), and has 31 Taiwan patents, and 15 US patents. Total citation is 1388+.

 

Novel Electronics

 

 

     

Material growth of SiGe quantum structures

In this project, we focus on the material growth of SiGe quantum structures, including SiGe QW, QDs and QRs, by ultrahigh vacuum chemical vapor deposition (UHVCVD) and their material property measurements.

 

 

Si/Ge MOSFET and HBT Devices

In this project, we focus on developing the low cost, high performance Ge MOSFETs, which is capable to replace Si as the future industry mainstream.

 

 

CMOS strain engineering

Under 90nm technology node, the strain engineering is the key technique to boost the channel mobility and enhance the performance of CMOS transistors.

 

 

IGZO Thin-Film-Transistors (TFTs)

The a-IGZO TFTs have higher on/off current ratio (~108) and higher carrier mobility (~28 cm2/ V-s) as compared to amorphous Si (a-Si) TFTs, and is suitable for the high performance applications.

 

 

Advanced material process

New SOI, GOI, SSDOI material using smart cut, wafer bonding, and nano-mechanics are developed for future device applications.

 

 

Carbon-based electronics: Graphene and GNRs

Graphene, a carbon-based 2D single atomic layer, is considered to be the potential material for the next generation electronic devices.

 

 

Device Modeling and Simulation

BSIM and Mextram models are being developed to take the strain and optical effects into account for RF and high speed digital applications. Finite element analyses of ISE-TACD and ANSYS are used to simulate Ge FET and MOS LED/GOI detector theoretically.

 

 

Photonics

 

 

 

              

Enhancements of direct band radiative recombination from Ge

The direct radiative transition in Ge is directly related to the material optical gain and the critical issue in Ge laser devices.

 

     

Epitaxial Ge optical devices

The epitaxial growth of thin film Ge-on-Si substrate is the key material structure for future electronic and photonic integrations.

 

 

CMOS photonic interconnect

Extremely small, highly efficient, and VLSI integratable devices are main purpose of this study. The high k material research is focused on these novel applications as well as gate stacks.

  

 

 

 

Photovoltaic


 

 

     

Quantum efficiency (QE), Photoluminescence (PL), Electroluminescence (EL), solar cell efficiency (including single, tandem and triple junction), dark and photo I-V measurement, carrier lifetime measurement by QSSPC, and FTPS for defect level.


 

 

     

Quantum efficiency (QE), solar cell efficiency, dark and photo I-V measurement, carrier lifetime measurement by QSSPC, and FTPS for defect level. 

 

     

Quantum efficiency (QE), Photoluminescence (PL), Electroluminescence (EL), solar cell efficiency , dark and photo I-V measurement. 

 


   

In this project, we focus on investigating the reliability of the a-Si based solar cells and improving light-trapping (optimizing the texture by simulation). The Quantum efficiency (QE), solar cell efficiency (including single, micromorph and triple junction), dark and photo I-V characteristics are also measured.

<!--[if gte mso 9]-->