發(fā)布時(shí)間：2018-06-15 02:52

  本文選題：微晶硅鍺薄膜 + 甚高頻等離子體增強(qiáng)化學(xué)氣相沉積��； 參考：《河北工業(yè)大學(xué)》2010年碩士論文

【摘要】：微晶硅鍺薄膜作為窄帶隙材料，具有吸收系數(shù)高、帶隙可調(diào)的優(yōu)點(diǎn)，是非常有前景的疊層太陽(yáng)電池的底電池吸收層材料。但薄膜中鍺的增加，使缺陷態(tài)增多，影響薄膜的光電性能，阻礙了其在太陽(yáng)能電池中的實(shí)際應(yīng)用。 本文分別以Si_2H_6和GeH_4及SiH_4和GeH_4兩種氣體組合為源氣體，用甚高頻等離子增強(qiáng)化學(xué)氣相沉積（VHF-PECVD）制備硅鍺薄膜，研究鍺對(duì)薄膜性能的影響。與SiH_4和GeH_4制備的薄膜系列相比，Si_2H_6和GeH_4制備的薄膜中鍺的融入速率相對(duì)較慢；同時(shí)Si_2H_6和GeH_4制備的硅鍺薄膜隨著鍺烷濃度的增加薄膜結(jié)構(gòu)始終保持一定的有序度。GeH_4與Si_2H_6生長(zhǎng)的薄膜在保持一定晶化比例的前提下，光敏性相對(duì)較高。與SiH_4相比，Si_2H_6在與GeH_4組合生長(zhǎng)微晶硅鍺薄膜有一定的優(yōu)勢(shì)。 采用Si_2H_6和GeH_4作為源氣體制備微晶硅鍺薄膜，通過調(diào)節(jié)反應(yīng)過程中襯底溫度、氣體總流量、等離子功率和壓強(qiáng)等參數(shù)，對(duì)微晶硅鍺薄膜進(jìn)行優(yōu)化。最終發(fā)現(xiàn)：隨著襯底溫度的增加，薄膜有序度增加；隨氣體總流量增加，薄膜的生長(zhǎng)速率增加，晶化率逐漸減小；隨著功率的增加材料的晶化率增加，但當(dāng)功率超過一定值時(shí)，，正離子對(duì)薄膜表面的轟擊增強(qiáng)，增加了缺陷生成的幾率并引起光電特性的劣化；反應(yīng)氣壓過大會(huì)造成薄膜趨于非晶化，反應(yīng)氣壓太小，容易造成缺陷態(tài)增加，降低薄膜質(zhì)量。 最終，在襯底溫度為190℃，鍺烷濃度為10%，輝光功率12W，壓強(qiáng)為100Pa的條件下，制備出晶化率為42.7%，鍺含量為20%，光敏性達(dá)到103量級(jí)以上的微晶硅鍺薄膜。
[Abstract]:As a narrow band gap material, microcrystalline silicon germanium film has the advantages of high absorption coefficient and adjustable band gap. It is a promising material for bottom cell absorption of laminated solar cells. However, the increase of germanium in the film leads to the increase of the defect state, which affects the photoelectric performance of the film and hinders its practical application in solar cells. SiGe thin films were prepared by VHF plasma enhanced chemical vapor deposition (VHF-PECVD) using Si2H6 and GeHCO4 and SiHST4 and GeHST4 gas combinations as source gases, respectively. The effect of germanium on the properties of SiGe thin films was studied. The incorporation rate of germanium in the films prepared by SiS _ 2H _ 6 and GeH _ S _ 4 is relatively slow compared with the films prepared by SiHs _ 4 and GeH _ S _ 4. At the same time, Si2H6 and Gehs _ 4 Si-germanium thin films kept a certain degree of order with the increase of the concentration of germanium. The Guang Min properties of the films grown by Si _ 2H _ 6 and Si _ 2H _ 6 were relatively high under the condition of keeping a certain ratio of crystallization to that of Si _ 2H _ 6. Compared with SiH _ (4), SiS _ (2) H _ (6) has some advantages in microcrystalline SiGe thin films grown in combination with GeHs _ (4). Si2H6 and Gehst4 were used as source gases to prepare microcrystalline SiGe thin films. The microcrystalline SiGe thin films were optimized by adjusting the substrate temperature, gas flux, plasma power and pressure. It is found that with the increase of substrate temperature, the order of the film increases, the growth rate of the film increases with the increase of the total gas flow rate, the crystallization rate decreases gradually, and the crystallization rate increases with the increase of power, but when the power exceeds a certain value, The positive ion bombardment on the surface of the film increases the probability of the formation of defects and leads to the deterioration of the photoelectric properties. The reaction pressure is too high and the reaction pressure is too small to lead to the increase of the defect state and the decrease of the film quality. Finally, under the conditions of substrate temperature of 190 鈩

本文編號(hào)：2020270