Download Free Remote Plasma Deposition Of Hydrogenated Amorphous Silicon Book in PDF and EPUB Free Download. You can read online Remote Plasma Deposition Of Hydrogenated Amorphous Silicon and write the review.

Semiconductors made from amorphous silicon have recently become important for their commercial applications in optical and electronic devices including FAX machines, solar cells, and liquid crystal displays. Plasma Deposition of Amorphous Silicon-Based Materials is a timely, comprehensive reference book written by leading authorities in the field. This volume links the fundamental growth kinetics involving complex plasma chemistry with the resulting semiconductor film properties and the subsequent effect on the performance of the electronic devices produced. Focuses on the plasma chemistry of amorphous silicon-based materials Links fundamental growth kinetics with the resulting semiconductor film properties and performance of electronic devices produced Features an international group of contributors Provides the first comprehensive coverage of the subject, from deposition technology to materials characterization to applications and implementation in state-of-the-art devices
In the crystalline Si solar cell industry, there is a push to reduce module cost through a combination of thinner substrates and increased cell efficiency. Achieving solar cells with sub-100 [greek small letter mu]m substrates cost-effectively is a formidable task because such thin substrates impose stringent handling requirements and thermal budget due to their flexibility, ease of breakage, and low yield. Moreover, as the substrate thickness decreases the surface passivation quality dictates the performance of the cells. Crystalline Si heterojunction (HJ) solar cells based on hydrogenated amorphous silicon (a-Si:H) have attracted significant interest in recent years due to their excellent surface passivation properties, potential for high efficiency, low thermal budget and low cost. HJ cells with ultra-passivated surfaces showing > 700 mV open-circuit voltages (Voc) and > 20% conversion efficiency have been demonstrated. In these cells, it has been identified that high-quality a-Si:H films deposited by a low-damage plasma process is key to achieving such high cell performance. However, the options for low-damage plasma deposition process are limited. The main objectives of this work are to develop a low-plasma damage a-Si:H thin film deposition process based on remote plasma chemical vapor deposition (RPCVD) and to demonstrate high efficiency HJ solar cells on bulk substrates as well as on ultra-thin silicon and germanium substrates obtained by a novel, low-cost semiconductor-on-metal (SOM) technology. This manuscript presents a detailed description of the RPCVD system and the process leading to the realization of high quality a-Si:H thin films and high efficiency HJ solar cells. First, p-type a-Si:H thin films are developed and optimized, then HJ solar cells are subsequently fabricated on bulk and ultra-thin Si and Ge SOM substrates without intrinsic a-Si:H passivation. Single HJ cells on ~ 500 μm bulk Si and ~25 μm ultra-thin substrates exhibited conversion efficiencies of [greek small letter eta] = 16% (Voc = 615 mV, Jsc = 34 mA/cm2, and FF = 77%) and [greek small letter eta] = 11.2% (Voc = 605 mV, Jsc = 29.6 mA/cm2, and FF = 62.8%), respectively. The performance of the ~25 [greek small letter mu] m cell was further improved to [greek small letter eta] = 13.4% (Voc = 645 mV, Jsc = 31.4 mA/cm2, and FF = 66.2%) by implementing the dual HJ architecture without front side i-layer passivation. For single HJ cells based on Ge substrates, the results were [greek small letter eta] = 1.78 % (Voc = 148 mV, Jsc = 35.1 mA/cm2, and FF = 1.78%) on ~500 [greek small letter mu]m bulk Ge, compared to [greek small letter eta] =5.3% (Voc = 203 mV, Jsc = 44.7 mA/cm2, and FF = 5.28%) on ~ 50 μm Ge SOM substrates. Respectively, the results obtained on ultra-thin SOM substrates are among the highest reported in literature for based on comparable architecture and substrate thickness. In order to achieve improved cell performance, dual HJ cells with i-layer passivation of both surfaces were fabricated. First, optimized RPCVD-based i-layer films were developed by varying the deposition temperature and H2 dilution ratio (R). It was found that excellent surface passivation on planar substrates with as-deposited minority carrier lifetimes > 1 ms is achievable by using deposition temperature of 200 oC and moderate dilution ratio 0.5 ≤ R ≤ 1, even without the more rigorous RCA pre-cleaning process typically used in literature for achieving comparable results. Subsequently, dual HJ solar cells with i-layer films were demonstrated on planar and textured bulk Si substrates showing improved conversion efficiencies of [greek small letter eta] = 17.3% (Voc = 664 mV, Jsc = 34.34 mA/cm2 and FF = 76%) and [greek small letter eta] = 19.4% (Voc = 643 mV, Jsc = 38.99 mA/cm2, and FF = 77.5%), respectively.
Hot Wire Chemical Vapor Deposition (HWCVD) is an emerging technology in semiconductor materials thin film deposition due to the high growth rates and reasonable electronic properties attainable using this method. To improve the electronic characteristics of material grown by the HWCVD method, neutral ion bombardment during growth was introduced as it is shown to be beneficial in Plasma Enhanced Chemical Vapor Deposition (PECVD). Neutral ion bombardment was accomplished by using remote Electron Cyclotron Resonance (ECR) plasma and the entire deposition technique is termed ECR-HWCVD. The ECR-HWCVD films were compared to HWCVD materials deposited without ion bombardment grown at similar conditions in the same reactor using a 10.5 cm filament to substrate distance to minimize substrate heating by radiation during deposition. The growth rate is halved when ion bombardment is added to HWCVD, however it remains four times greater than the highest quality ECR-PECVD films. Also, ECR-HWCVD material exhibited better electronic properties as shown by Urbach energy, photosensitivity, hydrogen content, microstructure parameters, and space charge limited current defect measurements. In addition, the effect of substrate temperature on hydrogen content and material microstructure was investigated. Both hydrogen content and the microstructure parameter R decreased as substrate temperature increased; and when ion bombardment was added to the deposition conditions, the microstructure parameter decreased regardless of substrate temperature.
Semiconductors made from amorphous silicon have recently become important for their commercial applications in optical and electronic devices including FAX machines, solar cells, and liquid crystal displays. Plasma Deposition of Amorphous Silicon-Based Materials is a timely, comprehensive reference book written by leading authorities in the field. This volume links the fundamental growth kinetics involving complex plasma chemistry with the resulting semiconductor film properties and the subsequent effect on the performance of the electronic devices produced. Key Features * Focuses on the plasma chemistry of amorphous silicon-based materials * Links fundamental growth kinetics with the resulting semiconductor film properties and performance of electronic devices produced * Features an international group of contributors * Provides the first comprehensive coverage of the subject, from deposition technology to materials characterization to applications and implementation in state-of-the-art devices
High-quality and low-cost fabrication of Si-based materials, in which many fundamental and technology problems still remain, have attracted tremendous interests due to their wide applications in solar cell area. Low-frequency inductively coupled plasma (LFICP) provides a new and competitive solution, thanks to its inherent advantages of high-density plasma, low sheath potential, and low electron temperature, et cetera The plasma characteristic-dependent microstructures, optical and electronic properties of the LFICP CVD-based hydrogenated amorphous/microcrystalline silicon and silicon oxides are systematically studied. Remote-LFICP combing the high-density plasma nature of ICP and mild ion bombardment on growing surface in remote plasma allows the deposition of high-quality Si-based materials providing excellent c-Si surface passivation. The mechanism of surface passivation by LFICP CVD Si-based materials, interaction between plasma species and growing surface are analyzed in terms of the plasma properties. These results pave the way for LFICP CVD utilization in Si-based high-efficiency and low-cost solar cell fabrication.
The realization of ultra high hydrogenated amorphous silicon (a-Si:H) growth rates (>10 A/s) is one of the main issues affecting cost reduction in the production process of thin film a-Si:H solar cells. Until now, the expanding thermal plasma (ETP) deposition technique and the hot-wire chemical deposition (HWCVD) technique are the only two techniques which have obtained good materials properties at ultra high growth rates of 100 A/s. To optimize the a-Si:H growth rate and the material properties, more insight into the a-Si:H growth is required. In this thesis the a-Si:H film properties deposited by means of the ETP technique are studied. Furthermore, the relation of the material properties with a-Si:H growth from the remote ETP deposition is studied.