Investigation of effects of polymer semiconductor blends on threshold voltage tuning of field effect transistors

In this project, inverters were fabricated using three different thiophenes (P3HT, PQT and PBTDT) as the semiconductor layer and were electrically tested. All three polymer based inverters showed good switching characteristics and gain of > 2. However, due to the positive threshold voltage, the s...

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Main Author: Tan, Zhen Hao.
Other Authors: Subodh Gautam Mhaisalkar
Format: Final Year Project
Language:English
Published: 2009
Subjects:
Online Access:http://hdl.handle.net/10356/15438
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-154382023-03-04T15:39:26Z Investigation of effects of polymer semiconductor blends on threshold voltage tuning of field effect transistors Tan, Zhen Hao. Subodh Gautam Mhaisalkar School of Materials Science and Engineering DRNTU::Engineering In this project, inverters were fabricated using three different thiophenes (P3HT, PQT and PBTDT) as the semiconductor layer and were electrically tested. All three polymer based inverters showed good switching characteristics and gain of > 2. However, due to the positive threshold voltage, the switching voltage shifted to more positive which is larger than the VDD, which then rendered its useless in organic circuit due to unmatching VIN to VOUT. Hence, for inverters to be functionable, threshold voltage control is essential. The project then moved into fabricating OFETs using different weight composition of polymer blends, to investigate the effect on tuning threshold voltage. In the second part of the project, a trend of threshold voltage shift was observed with mixing of thiophenes with different ionization energy (P3HT, PQT and PBTDT). The polymers were solution deposited by spin coating on silicon substrates with a double dielectric layer (silicon nitride and sol gel silica). Electrical characterization showed good mobilites, high on/off current ratios and good control of threshold voltage. Pure P3HT has positive threshold voltage of 5.71V and with addition of PQT and PBTDT, the threshold voltage shifted to the negative region. This method eliminates the extra fabrication step used to modify the dielectric interface which proves to tune the threshold voltage effectively. Bachelor of Engineering (Materials Engineering) 2009-04-30T01:14:13Z 2009-04-30T01:14:13Z 2009 2009 Final Year Project (FYP) http://hdl.handle.net/10356/15438 en Nanyang Technological University 48 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic DRNTU::Engineering
spellingShingle DRNTU::Engineering
Tan, Zhen Hao.
Investigation of effects of polymer semiconductor blends on threshold voltage tuning of field effect transistors
description In this project, inverters were fabricated using three different thiophenes (P3HT, PQT and PBTDT) as the semiconductor layer and were electrically tested. All three polymer based inverters showed good switching characteristics and gain of > 2. However, due to the positive threshold voltage, the switching voltage shifted to more positive which is larger than the VDD, which then rendered its useless in organic circuit due to unmatching VIN to VOUT. Hence, for inverters to be functionable, threshold voltage control is essential. The project then moved into fabricating OFETs using different weight composition of polymer blends, to investigate the effect on tuning threshold voltage. In the second part of the project, a trend of threshold voltage shift was observed with mixing of thiophenes with different ionization energy (P3HT, PQT and PBTDT). The polymers were solution deposited by spin coating on silicon substrates with a double dielectric layer (silicon nitride and sol gel silica). Electrical characterization showed good mobilites, high on/off current ratios and good control of threshold voltage. Pure P3HT has positive threshold voltage of 5.71V and with addition of PQT and PBTDT, the threshold voltage shifted to the negative region. This method eliminates the extra fabrication step used to modify the dielectric interface which proves to tune the threshold voltage effectively.
author2 Subodh Gautam Mhaisalkar
author_facet Subodh Gautam Mhaisalkar
Tan, Zhen Hao.
format Final Year Project
author Tan, Zhen Hao.
author_sort Tan, Zhen Hao.
title Investigation of effects of polymer semiconductor blends on threshold voltage tuning of field effect transistors
title_short Investigation of effects of polymer semiconductor blends on threshold voltage tuning of field effect transistors
title_full Investigation of effects of polymer semiconductor blends on threshold voltage tuning of field effect transistors
title_fullStr Investigation of effects of polymer semiconductor blends on threshold voltage tuning of field effect transistors
title_full_unstemmed Investigation of effects of polymer semiconductor blends on threshold voltage tuning of field effect transistors
title_sort investigation of effects of polymer semiconductor blends on threshold voltage tuning of field effect transistors
publishDate 2009
url http://hdl.handle.net/10356/15438
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