From Molecular Gallium and Indium Siloxide Precursors to Amorphous Semiconducting Transparent Oxide Layers for Applications in Thin‐Film Field‐Effect Transistors

Abstract

The syntheses, structural characterization, and thermal degradation of a series of the new indium and gallium siloxide dimers [{Me2In(OSiEt3)}2] (1), [{Me2Ga(OSiEt3)}2] (2), [{Me2In(OSi(OtBu)3)}2] (3), [{Me2Ga(OSi(OtBu)3)}2] (4), and In[OSi(OtBu)3)] (5) is reported. Compounds 1–4 are readily accessible by facile Brönsted reaction of InMe3 or GaMe3 with the corresponding silanols Et3SiOH and (tBuO)3SiOH, respectively. Compound 5 could be obtained by analogous protolysis of [In{N(SiMe3)2}3] with an excess amount of (tBuO)3SiOH. The suitability of 1–5 to serve as molecular precursors for low‐temperature synthesis of amorphous indium and gallium oxide for electronic applications was probed. Thus their thermal degradation was studied by Thermogravimetric/differential thermogravimetry analysis (TGA/DTG). Compounds 1–4 were decomposed under dry synthetic air (20 % O2, 80 % N2) at low temperature to yield amorphous indium oxide and gallium oxide particles, respectively. In contrast, thermal degradation of 5 affords amorphous indium silicate. All of these products were analyzed by multiple techniques including powder X‐ray diffraction analysis (PXRD), transmission electron microscopy (TEM), and energy dispersive X‐ray spectroscopy (EDX). Thin‐film field‐effect transistors (FETs) could be fabricated through spin‐coating of silicon‐wafers with solutions of 1 in toluene and subsequent calcination under dry synthetic air at 350 °C. These films exhibit very good FET performance with a field‐effect mobility of 3.0×10−1 cm2 V−1 s and an on/off current ratio of 108.

Solution based CVD of main group materials

“…Furthermore, varying the R group on the N donor atom can not only increase the steric demand of the ligand, but also, with use of a polyether for example, yield multidentate ligands. In addition to gallium alkoxides and b-ketoiminates, gallium siloxide compounds, of the type [Me 2 Ga(OR)] 2 (SiEt 3 , Si(O t Bu) 3 ), 169 have been reported and their thermal degradation to Ga 2 O 3 was proven via TGA. 17c and d, X = H) in comparison to [GaH 2 (L 4 )] resulting in transparent adherent films.…”

Nanostructured Manganese Oxides as Highly Active Water Oxidation Catalysts: A Boost from Manganese Precursor Chemistry

“…Moreover, the SSP approach facilitates rational access and shape selectivity of potential heterogeneous catalysts on the nanoscale; this itself is a significant challenge in the field of advanced functional inorganic materials. [70][71][72][73][74][75][76] In addition, the SSP route is particularly promising for the synthesis of materials that do not exist on the microscale and of which the activity and electronic properties can be easily tuned through shaping. This versatile approach has already been demonstrated for the preparation of amorphous transparent conducting oxides, which have shown remarkable long-term stability as well as high optoelectronic performance.…”

Inorganic heterocycles based on alumosilicate-sulfide ligand

“…322.6°C (dec); 1 H NMR (300.53 MHz, C 6 D 6 , 20°C): d (ppm) À0.38 (s, 3 H, AlMe), 1.11 (d, 3 J H-H = 6.7 Hz, 3 H, CHMe 2 ), 1.12 (m,4 H,AlO(CH 2 CH 2 ) 2 ), 1.15 (d, 3 J H-H = 6.7 Hz, 3 H, CHMe 2 ), 1. 18 (s, 9 H, CMe 3 ), 1.22 (s, 9 H, CMe 3 ), 1.26 (d, 3 J H-H = 6.7 Hz, 3 H, CHMe 2 ), 1.27 (d, 3 J H-H = 6.7 Hz, 3 H, CHMe 2 ), 1.42 (m,4 H,(O(CH 2 CH 2 ) 2 ), 1.44 (d, 3 J H-H = 6.7 Hz, 3 H, CHMe 2 ), 1.56 (s, 3 H, Me), 1.61 (s, 3 H, Me), 1.71 (d, 3 J H-H = 6.7 Hz, 3 H, CHMe 2 ), 1.72 (d, 3 J H-H = 6.7 Hz, 6 H, CHMe 2 ), 3.53 (m, 2 H, AlO(CH 2 CH 2 ) 2 ), 3.56 (sept, 3 J H-H = 6.7 Hz, 1 H, CHMe 2 ), 3.58 (m,4 H,(O(CH 2 CH 2 ) 2 ), 3.62 (sept, 3 J H-H = 6.7 Hz, 1 H, CHMe 2 ), 3.77 (m, 2 H, AlO(CH 2 CH 2 ) 2 ), 3.81 (sept, 3 J H-H = 6.7 Hz, 1 H, CHMe 2 ), 4.04 (sept, 3 J H-H = 6.7 Hz, 1 H, CHMe 2 ), 4.88 (s, 1 H, c-H), 6 H,; 13 124.2,124.5,125.0,126.8,127.4,127.9,141.0,141.0,144.9,145.3,145.4, 13 g mol -1 ): C,63.28;H,8.85;N,3.51. Found: C,63.0;H,8.6;N,3.2%.…”

“…1 ,9.27;N,3.16. Found: C,61.4;H,9. A solution of 1 (0.50 g, 0.73 mmol) in toluene (10 mL) was prepared inside a glove box and kept for at least 30 min. at À35°C in an integrated freezer.…”