Other Research
Amorphous / Nanocrystalline Silicon Schottky Diodes for High Frequency Rectification
Thin-film rectifiers, compatible with processing on plastic substrates, are key components for large-area electronic systems. In our systems Chip-on-flex ICs communicate with laminated large-area sheets via noncontact near-field inductive links; once an AC signal is received by the sheet it must be converted to DC. In these applications the inductive links function best at high frequencies, highlighting the need for thin-film diodes for AC-to-DC rectification at high frequencies.
I developed a hybrid amorphous silicon (a-Si) / nanocrystalline (nc-Si) silicon Schottky diode, fabricated at
180°C, making it compatible with processing on plastic. Also, it is grown using standard a-Si plasma-enhanced chemical vapor deposition (PECVD) equipment and requires no p-type doping, allowing for the possibility of manufacturing via a conventional a-Si TFT fabrication line used for AMLCDs. These diodes have the highest reported current density (5 A/cm2 at 1 V and 100 A/cm2 at 2 V) for this material system, providing a cutoff frequency of 110 MHz. Further information can be found in my Electron Device Letters paper.
I developed a hybrid amorphous silicon (a-Si) / nanocrystalline (nc-Si) silicon Schottky diode, fabricated at
180°C, making it compatible with processing on plastic. Also, it is grown using standard a-Si plasma-enhanced chemical vapor deposition (PECVD) equipment and requires no p-type doping, allowing for the possibility of manufacturing via a conventional a-Si TFT fabrication line used for AMLCDs. These diodes have the highest reported current density (5 A/cm2 at 1 V and 100 A/cm2 at 2 V) for this material system, providing a cutoff frequency of 110 MHz. Further information can be found in my Electron Device Letters paper.
Structural HEALTH MONIToring with tft Strain sensors
We developed a hybrid system for structural health monitoring, based on a-Si TFTs in the large-area domain for building a physically expansive array, and a CMOS IC, for readout and signal processing. I worked on adapting TFTs on a flexible substrate to function as strain sensors, taking advantage that their mobility is a function of the strain applied across the channel. This led me to develop a TFT based differential Gilbert cell, in which one of the tail TFTs was oriented to experience strain, while the other TFT was used as a reference and oriented to not experience strain. Since both TFTs degrade in a similar manner, this allowed the strain measurement to be resilient to the degradation of the TFTs over time. For more information here is our JSSC paper: