发表机构
University of Pittsburgh; National Taiwan University; Queen’s University; University of Maryland, College Park（匹兹堡大学; 国立台湾大学; 女王大学; 马里兰大学帕克分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过向GST中掺入Sn（5-10 at.%）降低相变光子开关的编程能量，实现节能非易失性开关，且不影响开关速度。
AI 中文摘要
集成相变光子学允许非易失性光学开关且无静态功耗，但可逆切换材料状态所需的电能限制了实际扩展。提高能效的努力大多集中在器件优化上，例如重新设计集成微加热器或波导。在此，我们采取一种不同的、以材料为中心的方法，将Sn合金化到Ge$_2$Sb$_2$Te$_5$（GST）中，而不改变器件结构或CMOS兼容性。我们探索了波导集成PN和PIN加热器上Sn浓度从0 at.%到20 at.%的范围，并观察到在5--10 at.%范围内非晶化和结晶能量均有所降低。在更高Sn含量下，这一趋势逆转，开关能量增加，结合TEM成分分析，这暗示了相分离。10 at.% Sn器件继续开关超过1000次循环，消光比从4.5 $\pm$ 0.3 dB可观察到退化至2.4 $\pm$ 0.3 dB。循环后成像显示PCM迁移和空洞形成，我们认为这可以通过增强封装进一步改善。总体而言，Sn合金化为集成相变光子学提供了一条降低编程能量的途径，且相对于未掺杂GST，不会对开关速度产生负面影响。
英文摘要
Integrated phase-change photonics allows non-volatile optical switching with no static power draw, but the electrical energy needed to reversibly switch the material's state limits practical scaling. Efforts to improve energy efficiency have mostly focused on device optimization, such as redesigning the integrated microheater or waveguide. Here, we take a different, materials-centered approach by alloying Sn to Ge$_2$Sb$_2$Te$_5$ (GST) without altering the device structure or CMOS compatibility. We explore Sn concentrations ranging from 0 at.% to 20 at.% on waveguide-integrated PN and PIN heaters and observe a reduction in both the amorphization and crystallization energies in the 5--10 at.% range. At higher Sn content this trend reverses and the switching energy increases, which is suggestive of phase segregation when combined with TEM compositional analysis. A 10 at.% Sn device continues to switch over 1000 cycles, with observable degradation in the extinction ratio from 4.5 $\pm$ 0.3 dB to 2.4 $\pm$ 0.3 dB. Post-cycling imaging shows PCM migration and void formation which we believe can be further improved by enhanced encapsulation. Overall, Sn alloying offers a route to lower programming energy in integrated phase-change photonics without negatively affecting the switching speed relative to un-doped GST.
