噴射式大氣電漿系統之廢熱回收與高霧度鎵摻雜氧化鋅透明導電薄膜製備

Energy Harvesting from Atmospheric Pressure Plasma Jet and Deposition of Hazy Ga-doped ZnO Thin Film

徐品嘉(Ping-Chia Hsu)

指導教授 ： 莊嘉揚

國立臺灣大學/工學院/機械工程學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202101684

摘要

隨著能源危機日益加劇，科學家紛紛研究如何有效利用製程中之各種能源，而其中廢熱回收為目前相當盛行之研究。本研究透過蒐集本實驗室自行架設之噴射式大氣電漿之熱能，並用以驅動一多功能感測系統幫助操作人員獲取溫度及槍體內空氣品質資訊，同時能自動將數據上傳至雲端資料庫。為了在有限空間中獲取足夠能量，將探討了三種熱電晶片組合，並且量測其電性，同時探討廢熱回收系統中，主動式散熱裝置的必要性。最後發現雙層熱電晶片在電路上為串聯時，為最適合當前多功能感測系統負載之熱電晶片組合，且開啟主動式散熱裝置後，可使熱電晶片載台底部溫度從90 °C降至42 °C，供電功率可從0.6 W上升至約1.09 W，使廢熱回收系統穩定運作至少17 分鐘。
再生能源中的太陽能電池也日益受到關注，其中，增加薄膜太陽能電池的前電極霧度不但能增加光的散射穿透度，使得入射光於太陽能電池中的路徑長增加，也能提高光封存的效果，進而提高太陽能電池的轉換效率。文獻中製備高霧度透明電極通常需要多次製程，常見的方法如：鍍製薄膜前預先在基板鋪上奈米銀線或奈米粒子、透過蝕刻薄膜增加表面粗糙度以及透過高溫基板(530 °C)來增加晶粒尺寸去增加表面粗糙度。本研究透過新增一層霧度增加層至標準製程薄膜之下，並調整霧度增加層之工作距離與步進距離進而改變薄膜之電學性質、光學性質及表面粗糙度，整個製程是可以一次完成，且與文獻相比使用較低溫之基板(180 °C)，以及不須切換機台及更換材料，既省時又能節省成本。研究中將探討霧度增加層對於上層薄膜之影響，以及上層薄膜厚度對於F.O.M及霧度之關聯性。其中當霧度增加層的工作距離增加時會使薄膜之結晶性下降及表面粗糙度上升，進而使得電性較差但霧度較高；而霧度增加層之步進距離增加時則會使上層薄膜結晶性較佳，粗糙度下降，電學性質較好，但是霧度也會跟著下降。在本研究中，最佳高霧度透明電極參數為當霧度增加層：WD = 4 mm, Pitch = 5 mm及標準製程薄膜：Pass = 3，此時F.O.M為 0.02089 Ω−1，而霧度達25%，於高霧度相關研究中有著優異的表現。

關鍵字

大氣電漿 ； 廢熱回收 ； 熱電晶片 ； 鎵摻雜氧化鋅 ； 高霧度透明電極 ； 光散射

並列摘要

As the energy crisis aggravate in recent year, scientists start finding how to recover the waste energy in various process. Among them, the thermoelectric generator is a rising research. Also, add the various sensors on the operation for monitoring is the cornerstone of Industry 4.0. In this research, we use the TEG to recover the waste heat from the self-constructed Atmospheric Pressure Plasma Jet (APPJ) of our lab, and use the electricity from the TEG to drive a multi-function monitoring system. A so-driven multi-functional monitoring system monitors processing temperature of the APPJ and air quality in the surroundings, transmits the data to a cloud storage, and alarms if the temperature or air quality exceeds a preset value. We study three different arrangements of TEGs and find that double TEGs connected in series thermally and electrically generate the most power of 1.09 0.0002 W at a current of 0.187 0.002 A, which is sufficient to drive the monitoring system continuously at least 17 min.
In numerous renewable energy, solar energy becomes promising because of its cost-efficiency and ease to produce. Increment of the haze of the front electrode in thin-film solar cell can enhance the power conversion efficiency because of the longer optical path and the level of light trapping. We deposit the haze enhanced layer under the standard process thin film, and through tuning the working distance and the pitch to change the electrical, optical, and surface roughness of the thin film. In previous literature, depositing hazy transparent conductive thin film needs either multiple processes or high substrate temperature. However, they would make the process inefficient, and the choice of the substrate might be limited. Therefore, our method can produce the high haze transparent electrode in one step, and it’s unnecessary to change the precursor or machine like the literature mentioned. It can also be deposited at the lower substrate temperature (~180 °C), so the limitation of the substrate can be reduced. In this research, we find that the surface roughness increase and crystallinity decrease as the working distance increase, which causes the higher resistivity and haze; after increasing the pitch, the surface roughness decrease and the crystallinity rise, so the better electrical properties but lower haze. The best parameters of high haze electrode in this research are the Working distance of the haze enhanced layer = 4 mm、Pitch of the haze enhanced layer = 5 mm、Pass of standard process thin film = 3, which show the high F.O.M value: 0.02089 Ω−1 and high haze: 25% and it has pretty high competitiveness in the hazy transparent conductive thin film literature.

並列關鍵字

Intelligent machines ； Atmosphere pressure plasma jet (APPJ) ； Waste heat recovery ； Thermoelectric generator (TEG) ； Sensing and monitoring ； Gallium doped Zinc Oxide (GZO) ； High haze electrode ； Light scattering

參考文獻

[1] J. Y. Kwon et al., "Bottom-gate gallium indium zinc oxide thin-film transistor array for high-resolution AMOLED display," IEEE Electron Device Letters, vol. 29, no. 12, pp. 1309-1311, 2008.

[2] K. Ellmer, "Past achievements and future challenges in the development of optically transparent electrodes," Nature Photonics, vol. 6, no. 12, pp. 809-817, 2012.

[3] Y. Gao, X. Li, L. Chen, J. Shi, X. W. Sun, and J. Zhang, "High mobility solution-processed hafnium indium zinc oxide TFT with an Al-doped ZrO2 gate dielectric," IEEE Electron Device Letters, vol. 35, no. 5, pp. 554-556, 2014.

[4] A. Hongsingthong, T. Krajangsang, I. A. Yunaz, S. Miyajima, and M. Konagai, "ZnO films with very high haze value for use as front transparent conductive oxide films in thin-film silicon solar cells," Applied Physics Express, vol. 3, no. 5, 2010, doi: 10.1143/apex.3.051102.

[5] J. Krc et al., "Potential of thin-film silicon solar cells by using high haze TCO superstrates," Thin Solid Films, vol. 518, no. 11, pp. 3054-3058, 2010, doi: 10.1016/j.tsf.2009.09.164.