论文标题
使用闪光灯退火在碳化硅中形成硅纳米晶体
Formation of silicon nanocrystals in silicon carbide using flash lamp annealing
论文作者
论文摘要
During the formation of Si nanocrystals (Si NC) in Si$_x$C$_{1-x}$ layers via solid-phase crystallization, the unintended formation of nanocrystalline SiC reduces the minority carrier lifetime and therefore the performance of Si$_x$C$_{1-x}$ as an absorber layer in solar cells.退火时间的显着减少可以抑制SIC基质的结晶，同时保持Si NC的形成。在这项研究中，我们使用常规的快速热退火（RTA）和非平衡毫秒范围闪光灯退火（FLA）研究了化学计量SIC和富含SI的SIC的结晶。调查的Si $ _x $ C $ _ {1-X} $由等离子增强化学蒸气沉积制备，并在700 $ $ c至1100 $°C的RTA和34 j/cm $^2 $^2 $^2 $^2 $^2 $^2 $^j/cm $ $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2 $^2。进行了GixRD和FTIR，以研究氢积液，SI和SIC NC生长以及SIC结晶度。 SI含量和退火过程的选择都会影响结晶行为。结果表明，在某些条件下，FLA可以成功地用于SIC矩阵中Si NC的形成，该矩阵与RTA实现的SIC矩阵密切相似。样品必须具有多余的Si，并且闪光能不应超过40 j/cm $^2 $和47 j/cm $^2 $的Si $ _ {0.63} $ C $ _ {0.37} $和SI $ _ {0.77} $ C $ _ {0.77} $ C $ _ {0.23} $样品。在这些条件下，FLA成功地生产了给定尺寸的Si NC，其结晶性SIC比RTA少。使用经典结晶理论来讨论该结果的成核和晶体生长。对于FLA和RTA样品，观察到NC大小和Si含量之间的相反关系归因于H积液对Si含量的依赖性或材料的光吸收特性，这也取决于Si含量。
During the formation of Si nanocrystals (Si NC) in Si$_x$C$_{1-x}$ layers via solid-phase crystallization, the unintended formation of nanocrystalline SiC reduces the minority carrier lifetime and therefore the performance of Si$_x$C$_{1-x}$ as an absorber layer in solar cells. A significant reduction in the annealing time may suppress the crystallization of the SiC matrix while maintaining the formation of Si NC. In this study, we investigated the crystallization of stoichiometric SiC and Si-rich SiC using conventional rapid thermal annealing (RTA) and nonequilibrium millisecond range flash lamp annealing (FLA). The investigated Si$_x$C$_{1-x}$ films were prepared by plasma-enhanced chemical vapor deposition and annealed at temperatures from 700$°$C to 1100$°$C for RTA and at flash energies between 34 J/cm$^2$ and 62 J/cm$^2$ for FLA. GIXRD and FTIR were conducted to investigate hydrogen effusion, Si and SiC NC growth, and SiC crystallinity. Both the Si content and the choice of the annealing process affect the crystallization behavior. It is shown that under certain conditions, FLA can be successfully utilized for the formation of Si NC in a SiC matrix, which closely resembles Si NC in a SiC matrix achieved by RTA. The samples must have excess Si, and the flash energy should not exceed 40 J/cm$^2$ and 47 J/cm$^2$ for Si$_{0.63}$C$_{0.37}$ and Si$_{0.77}$C$_{0.23}$ samples, respectively. Under these conditions, FLA succeeds in producing Si NC of a given size in less crystalline SiC than RTA does. This result is discussed in terms of nucleation and crystal growth using classical crystallization theory. For FLA and RTA samples, an opposite relationship between NC size and Si content was observed and attributed either to the dependence of H effusion on Si content or to the optical absorption properties of the materials, which also depend on the Si content.
