Selective Chemical Vapor Deposition Approach for Sb₂Te₃ Thin Film Micro-thermoelectric Generators

Abstract

Micro-thermoelectric generators are attractive for autonomous sensor systems. This work reports an approach for fabricating thin film micro-thermoelectric generators via selective chemical vapor deposition. The approach utilizes our single source precursors which enable the production of high-quality thermoelectric materials, as exemplified by Sb2Te3 in this work. It also allows great control over the thermoelectric properties of the as-deposited Sb2Te3 by simply varying the deposition temperature. A competitive power factor of 16.5 µW/cm•K 2 can be obtained for a Sb2Te3 films deposited at 364ºC, with the highest estimated ZT value of 0.65. The selective deposition over the conductive TiN surface enables the fabrication of a prototype single-leg

nBu2Sn(SnBu)2 and nBu3SnEnBu (E = S or Se) – effective single source precursors for the CVD of SnS and SnSe thermoelectric thin films

“…Some SSPs have also been shown to allow for selective deposition of materials into patterned substrates. [25][26][27][28][29][30][31] The use of low pressure CVD with SSPs is especially beneficial when compared to the above deposition techniques as the precursors suitable for LPCVD are the most versatile and more transferable to other deposition methodologies.…”

Recent Advances in the Nanomaterials, Design, Fabrication Approaches of Thermoelectric Nanogenerators for Various Applications

“…One of the most important aspects to consider when using metal tellurides is the scarcity and high cost of tellurium, so various methods have been developed to minimize tellurium use. [55] For example, Newbrook et al [20] used low-pressure chemical vapor deposition (CVD) to reduce tellurium waste by 87% in fabricating the Sb 2 Te 3 TE legs compared to the traditional sputtering method. Compared to other commonly used deposition procedures, such as sputter deposition, [56] CVD enabled highly selective deposition onto a lithographically patterned substrate, unlike the sputtering process that required reactive ion etching to shape the TE legs.…”

Low temperature CVD of thermoelectric SnTe thin films from the single source precursor, [nBu3Sn(TenBu)]

“…It is worth mentioning that the selective deposition behaviour allows great positional control over the material growth and is beneficial for the fabrication of micro-thermoelectric generators. 44…”