Growth of hole-conducting Cu2O & CuO semiconductors using CVD for next-generation electronic devices: (Record no. 429664)
[ view plain ]
| 000 -LEADER | |
|---|---|
| fixed length control field | 06217nam a22002057a 4500 |
| 008 - FIXED-LENGTH DATA ELEMENTS--GENERAL INFORMATION | |
| fixed length control field | 230913b |||||||| |||| 00| 0 eng d |
| 082 ## - DEWEY DECIMAL CLASSIFICATION NUMBER | |
| Classification number | 621.3815 SIN |
| 100 ## - MAIN ENTRY--PERSONAL NAME | |
| Personal name | Singh, Vivek |
| 245 ## - TITLE STATEMENT | |
| Title | Growth of hole-conducting Cu2O & CuO semiconductors using CVD for next-generation electronic devices: |
| Remainder of title | thin films transistors, memristors, and gas sensors |
| 260 ## - PUBLICATION, DISTRIBUTION, ETC. (IMPRINT) | |
| Place of publication, distribution, etc | Bangalore : |
| Name of publisher, distributor, etc | Indian Institute of Science, |
| Date of publication, distribution, etc | 2023 |
| 300 ## - PHYSICAL DESCRIPTION | |
| Extent | 185p.: |
| Other physical details | ill. col. |
| Accompanying material | e-Thesis |
| Size of unit | 9.069 Mb |
| 500 ## - GENERAL NOTE | |
| General note | includes bibliographical references and index |
| 502 ## - DISSERTATION NOTE | |
| Dissertation note | PhD; 2023; Centre for Nano Science and Engineering |
| 520 ## - SUMMARY, ETC. | |
| Summary, etc | Semiconducting oxides with visible-range transparency and high electrical conductivity have<br/>tremendous potential for transparent CMOS devices. Oxide semiconducting materials are a good<br/>choice for emerging transparent electronics due to their stability, good transparency, wide<br/>bandgap, and low processing temperature. However, oxide semiconductors arelagging in<br/>electrical properties compared to single-crystal silicon. Still, they give excellent competition to<br/>amorphous silicon with low cost of production and eco-friendly nature.<br/>Transparent electronic applications are limited by the lack of availability of p-type oxide<br/>semiconductors with adequate performance. In digital electronics, a p-type oxide transistor is a<br/>key component of CMOS devices, but due to the unavailability of a p-type oxide transistor<br/>semiconductor with performance comparable to n-type, it's challenging to develop a highperformance transparent CMOS device. So, p-type oxides are the primary culprit and bottleneck<br/>in achieving high performance in their devices. Although much effort has been put into P-N<br/>junction devices such as solar cells, LEDs, and CMOS electronics, their performance is still limited.<br/>The only applications that can be accomplished to date are based on n-type oxide<br/>semiconductors. If high-performance p-type oxide semiconductors can be synthesized, it will<br/>usher in a new age of next-generation transparent electronics devices that will impact many<br/>aspects of our everyday life.<br/>The main reason for this discrepancy lies in the difference in the low mobility of holes in p-type<br/>oxide semiconductors compared to the high electron mobility of n-type oxide semiconductors,<br/>as the effective mass of electrons is lower than the effective mass of holes. There is a vast list of<br/>n-type oxide semiconductors with low effective mass; however, there are relatively few p-type<br/>oxide semiconductor materials. Unfortunately, none have a comparable effective mass.<br/>Cu2O is a rare transition-metal oxide with a bandgap of 2.2 eV and one of the few oxides that<br/>show p-type conductivity with high Hall mobility. Unlike other p-type semiconductor metaloxides, Cu2O has the high hole mobility needed for transparent electronics. Unfortunately, the<br/>thin-film deposition of pure Cu2O is not trivial, especially with physical vapour deposition (PVD). Pure phase Cu2O is formed in a narrow pressure-temperature window, only under precise oxygen<br/>potential. Therefore, we have deposited Cu2O using CVD. For device-grade films, chemical vapour<br/>deposition (CVD) is superior, as it allows a more robust control of deposition parameters, leading<br/>to better uniformity, topology control, and step coverage over large areas. CVD also gives the<br/>freedom to control the supersaturation, so crystallinity, morphology, and grain size can be<br/>engineered, which plays a significant role in device performance.<br/>As previous literature states, theoretically, Cu2O has the potential to show good mobility, but<br/>unfortunately, the performance of the reported device is neither remarkable nor consistence.<br/>Therefore, to achieve a better performance in this work, we fabricated the TFTs using CVD-grown<br/>Cu2O with high Hall mobility on four dielectrics. We have also investigated the origin of poor<br/>device characteristics in conventional reposted Cu2O-TFTs. We have also proposed a systematic<br/>approach to passivating these interface traps, improving the field-effect mobility, subthreshold<br/>swing, threshold voltage, and enhanced gate-bias-voltage stressing stability.<br/>The bottleneck of efficient implementation of CMOS data handing is challenging due to the<br/>‘memory wall’. A memristor with tunable resistance is an ideal building block for storing memory.<br/>As a memristor is an emerging fourth electronic element, lots of work must be done in the<br/>material process engineering domain. Here, we have proposed CVD deposited resistive switching<br/>layers memristor. In this work, the device stack of the memristor contains an intrinsic defective<br/>layer of cupric oxide (CuO) and cuprous oxide (Cu2O) sandwiched between electrodes. These<br/>Cu2O and CuO layers were deposited at four different temperatures (300C, 400C, 500C, and<br/>600C). Electrical and material characterizations illustrate that grains or corresponding grain<br/>boundaries play a vital role in controlling the switching behavior. Overall, we demonstrate good<br/>consistency in device parameters such as reproducibility, endurance, and retention data for the<br/>film deposited at 600C.<br/>Further, several micro and nanostructures of Cu2O have been utilized in gas sensing of oxidizing<br/>and reducing gases. However, large-area Cu2O films are needed for the mass production of<br/>sensors, which was a challenge. In this work, we also report a chemiresistive gas sensor based on<br/>pure-phase Cu2O deposited by chemical vapour deposition (CVD). The sensing results of Cu2O films have been explained from the standpoint of roughness, morphology, and unpassivated<br/>bonds present on the surface of films. At an operating temperature of 200℃, the sensor is highly<br/>sensitive to ammonia. The device's response time (𝛕response) and recovery time (𝛕recovery)<br/>were found to be decent for practical applications. Unlike competing techniques for Cu2O<br/>deposition, Cu2O from chemical vapour deposition leads to more repeatable, stable, and<br/>reproducible sensors. |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Thin Films Transistors |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Memristors |
| 700 ## - ADDED ENTRY--PERSONAL NAME | |
| Personal name | advised by Avasthi, Sushobhan and Jain, Manish |
| 856 ## - ELECTRONIC LOCATION AND ACCESS | |
| Uniform Resource Identifier | https://etd.iisc.ac.in/handle/2005/6208 |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) | |
| Koha item type | Thesis |
No items available.
