熱電元件可直接將熱能轉換為電能，亦可反向將電能轉換為熱能，且具有體積小、低噪音及高可靠性等優點，因此在廢熱回收與熱電致冷方面具有相當大的應用潛力。碲化鍺（GeTe）因具有優異的熱電潛力，是中溫熱電應用中最具發展前景的材料之一。然而，GeTe 薄膜的實際應用長期受到碲（Te）揮發所引起之熱不穩定性所限制，進而導致薄膜結構完整性與熱電性質劣化。傳統增加材料熱可靠度方式多仰賴元素摻雜以提升其熱穩定性。本研究證實，GeTe 薄膜的初始結晶性在決定其微結構演化與熱電性質表現方面具有關鍵影響。透過特定的熱處理條件，可使 GeTe 薄膜進入一種獨特的類理想玻璃非晶狀態，並從根本上改變其在高溫處理過程中的擴散動力學。不同於初始為結晶態的GeTe 薄膜，在熱時效過程因 Te 揮發導致孔洞形成而逐漸劣化的薄膜。類理想玻璃非晶GeTe薄膜在熱時效過程中自發重組為穩定的 a-Ge/GeTe/a-Ge 三明治結構。非晶 Ge 層一方面可作為自我鈍化屏障以抑制 Te 持續揮發，另一方面亦作為高遷移率的導電通道。因此，最佳化後的薄膜在經長時間高溫儲存後，仍能維持優異的結構完整性，且其功率因子較初始為結晶態的 GeTe 薄膜提升約 30%。;Germanium telluride (GeTe) is one of the most promising thermoelectric materials for medium-temperature applications because of its favorable thermoelectric potential. Thermoelectric devices， which can directly convert heat into electricity and vice versa， are attractive for waste heat recovery and thermoelectric cooling owing to their compactness， low noise， and high reliability. However， the practical application of GeTe thin films has long been hindered by thermal instability caused by tellurium (Te) volatilization， which degrades film integrity and thermoelectric performance. Conventional approaches mainly rely on elemental doping to improve thermal stability. In this study， it is demonstrated that the initial crystallinity of GeTe thin films plays a decisive role in determining their microstructural evolution and thermoelectric properties. Through specific thermal processing， GeTe thin films can be driven into a unique ideal-glass-like amorphous state， which fundamentally alters the diffusion kinetics during high-temperature treatment. Unlike initially crystalline films， which gradually degrade through void formation induced by Te volatilization， these amorphous films spontaneously reorganize into a stable a-Ge/GeTe/a-Ge sandwich structure during thermal aging. The amorphous Ge layers serve as self-passivating barriers that suppress continuous Te loss while also acting as high-mobility conduction channels. As a result， the optimized films maintain excellent structural integrity after prolonged hot storage and exhibit a power factor approximately 30% higher than that of initially crystalline GeTe thin films.
