Dielectric Properties of La³⁺at A Site and Al³⁺and Ga³⁺Doped at B Site in BaTiO₃

Bobade, Santosh Mahadeorao,Gopalan, Prakash,Choi, Duck-Kyun IOP Publishing 2009 Japanese journal of applied physics Vol.48 No.r4

Uniform Crystallization of a 300 Amorphous-Si TFT Array Employing Field-Aided Lateral Crystallization

김명호,정재훈,Santosh M. Bobade,최덕균,김영배,신지훈 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.5

In high-resolution displays, such as liquid crystal displays and organic light emitting diode displays, pixel-to-pixel uniformity in the panel is one of the most important requirements. In this study, a 120 × 320 thin-film transistor (TFT) array was fabricated on three-inch glass substrates by using Ni-induced, field-aided lateral crystallization (FALC) to improve the crystallization uniformity of a-Si below 500 ˚C. Two specially-designed common electrodes connecting the sources and the drains of the transistors in the array enabled application of a uniform electric field to the individual transistors during the FALC process. Thermal annealing at 500 ˚C for 4 hours completely crystallized the 20-μm-long channels of the TFTs. The degree of crystallization and the electrical properties of the TFTs were very uniform with a deviation of less than a few percent, which indicates that the proposed common electrode design and the FALC process can be used in applications. In high-resolution displays, such as liquid crystal displays and organic light emitting diode displays, pixel-to-pixel uniformity in the panel is one of the most important requirements. In this study, a 120 × 320 thin-film transistor (TFT) array was fabricated on three-inch glass substrates by using Ni-induced, field-aided lateral crystallization (FALC) to improve the crystallization uniformity of a-Si below 500 ˚C. Two specially-designed common electrodes connecting the sources and the drains of the transistors in the array enabled application of a uniform electric field to the individual transistors during the FALC process. Thermal annealing at 500 ˚C for 4 hours completely crystallized the 20-μm-long channels of the TFTs. The degree of crystallization and the electrical properties of the TFTs were very uniform with a deviation of less than a few percent, which indicates that the proposed common electrode design and the FALC process can be used in applications.

Graphene derivatives: Properties and potential food applications

Swati Joshi,Hanuman Bobade,Rajan Sharma,Savita Sharma 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.123 No.-

Graphene and its derivatives have been recently investigated for their potential applications in food processingindustry. Graphene derivatives have successfully plunged into packaging and electrochemicalsensing trades of the food industry. However, their multitudinous applications in the field of analytics,milk and beverage technology are still unexplored. This bibliographic review aims to enlighten the potentialapplications of graphene derivatives for the food industry. It summarizes derivatives of graphene,their distinctive properties and specific applications in food. A detailed overview of utilization of graphenederivatives as bio-composites; intelligent and active packaging; detection of pesticides, antinutrients;desalination and water treatment; extraction; production of tailored milk is provided. The graphenederivatives possessed several suitable and versatile properties for its potential applications in food processing. Graphene could be used as potent packaging and sensing materials. Also, graphene possessedantifouling properties and are excellent membrane for lactose removal from milk and water desalination. Toxicity studies refuted any major cytotoxicity, thereby escalating their scope in several aspects of foodtechnology. Further detailed research is required to study their migration behavior and design simplifiedmethods for its prevention. Ample scope of research is available for utilizing graphene in various segmentsof food production.

The Effects of Rapid Thermal Annealing on the Performance of ZnO Thin-Film Transistors

Chan Jun Park,김영웅,조영제,S. M. Bobade,최덕균,Sung Bo Lee 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.5

We fabricated and characterized zinc oxide (ZnO)-based thin-film transistors (TFTs) on a glass substrate, which can also be applied to plastic substrates such as polyimide or polynorbornene, at a maximum process temperature of 300 ˚C. Most of the component layers in ZnO-TFTs with a bottom-gate configuration were deposited by using rf magnetron sputtering techniques, except for the SiO2 gate insulating layer, which was deposited by using inductively coupled plasma chemical vapor deposition (ICP-CVD). Silicon-dioxide (SiO2) and ZnO layers were separately heat-treated at 300 ˚C by rapid thermal annealing (RTA) to study its effect on the device performance. The RTAtreated film had a surface morphology similar to that of the as-deposited film, but demonstrated higher crystallinity and transmittance, in addition to enhanced electrical properties, such as carrier concentration and mobility. When the SiO2 layer was RTA-treated before the ZnO deposition, the ZnO TFTs showed high field effect mobility and high on/off current ratio. As a result of the lowtemperature RTA treatment, we successfully fabricated high-performance and highly-transparent ZnO-TFTs. This process should be promising for various displays, such as organic light emitting diode (OLED) and liquid crystal display (LCD) that require low-temperature processes. We fabricated and characterized zinc oxide (ZnO)-based thin-film transistors (TFTs) on a glass substrate, which can also be applied to plastic substrates such as polyimide or polynorbornene, at a maximum process temperature of 300 ˚C. Most of the component layers in ZnO-TFTs with a bottom-gate configuration were deposited by using rf magnetron sputtering techniques, except for the SiO2 gate insulating layer, which was deposited by using inductively coupled plasma chemical vapor deposition (ICP-CVD). Silicon-dioxide (SiO2) and ZnO layers were separately heat-treated at 300 ˚C by rapid thermal annealing (RTA) to study its effect on the device performance. The RTAtreated film had a surface morphology similar to that of the as-deposited film, but demonstrated higher crystallinity and transmittance, in addition to enhanced electrical properties, such as carrier concentration and mobility. When the SiO2 layer was RTA-treated before the ZnO deposition, the ZnO TFTs showed high field effect mobility and high on/off current ratio. As a result of the lowtemperature RTA treatment, we successfully fabricated high-performance and highly-transparent ZnO-TFTs. This process should be promising for various displays, such as organic light emitting diode (OLED) and liquid crystal display (LCD) that require low-temperature processes.

The effect of annealing in forming gas on the a-IGZO thin film transistor performance and valence band cut-off of IGZO on SiNx

Raj Kamal,Piyush Chandravanshi,최덕균,Santosh M. Bobade 한국물리학회 2015 Current Applied Physics Vol.15 No.5

In this investigation, the carrier concentration gradient between channel and contact region is achieved to improve the Thin film Transistors (TFT) performance by employing annealing at 350 ℃ in forming gas (N2 + 5% H2). The contact region is covered with Mo metal and the channel region is only exposed to forming gas to facilitate the diffusion controlled reaction. The TFT using a-IGZO active layer is fabricated in ambient of Ar:O2 in ratio 60:40 and the conductivity of the order of 10-3 S/cm is measured for asdeposited sample. The electrical conductivity of an annealed sample is of the order of 102 S/cm. The device performance is determined by measuring merit factors of TFT. The saturation mobility of magnitude 18.5 cm2V-1 s-1 has been determined for W/L (20/10) device at 15 V drain bias. The extrapolated field effect mobility for a device with channel width (W) 10 mm is 19.3 cm2V-1 s-1. The on/ off current ratio is 109 and threshold voltage is in the range between 2 and 3 V. The role of annealing on the electronic property of a-IGZO is carried out using X-ray photoelectron spectroscopy (XPS). The valance band cut-off has been approximately shifted to higher binding energy by 1 eV relative to asdeposited sample.

Synthesis and Biological Screening of Thiazole-5-Carboxamide Derivatives

Mhaske, Pravin C.,Vadgaonkar, Kamlesh S.,Jadhav, Rahul P.,Bobade, Vivek D. Korean Chemical Society 2011 대한화학회지 Vol.55 No.5

Fabrication of an a-IGZO thin film transistor using selective deposition of cobalt by the self-assembly monolayer (SAM) process.

Cho, Young-Je,Kim, HyunHo,Park, Kyoung-Yun,Lee, Jaegab,Bobade, Santosh M,Wu, Fu-Chung,Choi, Duck-Kyun American Scientific Publishers 2011 Journal of Nanoscience and Nanotechnology Vol.11 No.1

<P>Interest in transparent oxide thin film transistors utilizing ZnO material has been on the rise for many years. Recently, however, IGZO has begun to draw more attention due to its higher stability and superior electric field mobility when compared to ZnO. In this work, we address an improved method for patterning an a-IGZO film using the SAM process, which employs a cost-efficient micro-contact printing method instead of the conventional lithography process. After a-IGZO film deposition on the surface of a SiO2-layered Si wafer, the wafer was illuminated with UV light; sources and drains were then patterned using n-octadecyltrichlorosilane (OTS) molecules by a printing method. Due to the low surface energy of OTS, cobalt was selectively deposited on the OTS-free a-IGZO surface. The selective deposition of cobalt electrodes was successful, as confirmed by an optical microscope. The a-IZGO TFT fabricated using the SAM process exhibited good transistor performance: electric field mobility (micro(FE)), threshold voltage (V(th)), subthreshold slope (SS) and on/off ratio were 2.1 cm2/Vs, 2.4 V, 0.35 V/dec and 2.9 x 10(6), respectively.</P>