Growth of PbS thin films from novel precursors by atomic layer epitaxy

Abstract

Two lead tert-butoxide complexes (1) [Pb(OBu')& (rn = 3 or 2 in the solid and gaseous phase, respectively) and (2) Pb,0(OBu')6 were used as precursors for atomic layer epitaxy (ALE) deposition of PbS thin films. The growth on soda lime glass, with and without an alumina coating, was studied by varying the source furnace and the substrate temperatures as well as the total number of cycles. Pb(thd), (3) and Pb(dedtc), (4) were used for comparison while H2S served in all experiments as the sulfur source.? The films obtained were smooth and generally highly crystalline.The substrate temperature had a strong effect on the growth rate of PbS thin films. Nevertheless, in the self-controlled region of ALE growth the tert-butfxide complexes gave a significantly higher growth rate than the other source chemicals, with a maximum of 0.9 A per cycle at 150 "C. Upon sublimation 1 is converted to 2, which contains four Pb atoms in a tetrahedral arrangement; this may cause the higher growth rate. Thermogravimetry/differential thermal analysis curves and mass spectrometric data were measured for all precursors. As the butoxide and thd complexes (1 -3) are thermally unstable the useful ALE prosessing windows (temperature/pressure) are narrow compared to the much more stable dedtc complex (4).

Atomic Layer Deposition of Titanium Disulfide Thin Films

“…A number of ALD processes for preparing various sulfides are described in the literature. These include processes for BaS, CaS, and SrS, [13] CdS, [14,15] CuS, [16] CuGaS 2 , [17] CuInS 2 , [18] In 2 S 3 , [19] La 2 S 3 , [20] PbS, [21] WS 2 , [22] and ZnS. [23,24] However, to our knowledge, no processes for the ALD of TiS 2 have so far been reported.…”

Physical properties of pulse electrodeposited lead sulfide thin films

“…PbS thin films can be obtained by different deposition techniques such as vacuum evaporation [10], successive ionic layer adsorption and reaction (SILAR) [11], chemical vapor deposition (CVD) [12], electrodeposition (ED) [13][14][15][16], and chemical bath deposition (CBD) [17,18]. Among the above mentioned methods CBD and ED are mostly used as low cost film growth techniques.…”

A solution-based ALD route towards (CH3NH3)(PbI3) perovskite via lead sulfide films

“…[15][16][17][18] PbS is also accessible via traditional gasphase ALD based on highly toxic, not inexpensive, volatile molecular lead precursors. [19][20][21] The current paper establishes a simple, low-cost sALD method to PbS lms with reduced health hazard. The data evidence the high purity and crystallinity of the deposit obtained at room temperature via solution processing.…”