Exploring the functional properties of PVP/PVA blend incorporated with non-stoichiometric SnS for optoelectronic devices

Figures & data

Figure 1. FTIR spectra of the samples.

Figure 2. (a) The transmittance and (b) absorbance spectra of the samples.

Figure 3. Plots of the absorption coefficient (a) and Tauc’s (b and c) of pure and incorporated PVP/PVA films.

Figure 4. The dependence of E_g value of pure and incorporated PVP/PVA films on the Sn/S ratio.

Table 1. The E_g and E_u values of pure and PVP/PVA incorporated with SnS_x films.

S/Sn molar ratio	Eg. Abs (eV)	Egd (eV)	Egi (eV)	Eu (eV)
Pure PVP/PVA	5.07	5.20	4.95	0.18
0.8	3.72	4.27	3.41	0.4
0.9	3.30	3.91	2.98	0.44
1.0	3.23	3.83	2.87	0.45
1.1	3.14	3.74	2.77	0.54
1.2	2.97	3.62	2.51	0.74

Figure 5. Plots of ln (α) vs hν of pure and incorporated PVP/PVA films.

Figure 6. Plots of refractive index vs. wavelength of pure and incorporated PVP/PVA films. The inset shows n dependence on the Sn/S ratio of the filler SnS.

Figure 7. The dielectric permittivity (a) real and (b) imaginary parts of the pure and incorporated PVP/PVA films vs. λ.

Figure 8. Plots of (a) (n²-1)⁻¹ vs. (hν)², (b) (n²-1)⁻¹ vs. λ⁻² and (c) n² vs. λ² of of the pure and incorporated PVP/PVA films.

Table 2. The optical properties of pure and incorporated PVP/PVA films.

Sulfur molar ratio	Ed (eV)	E0 (eV)	n${}_{\mathrm{\infty }}$	λ0 (nm)	S0 (x10^13m^−2)	ε${}_{\mathrm{\infty }}$	εL	(N/m*) × 10^57 (kg^−1.m^−3)
Pure PVP/PVA	6.57	5.85	1.45	228	2.13	2.11	2.41	0.5
0.8	7.03	3.73	1.75	321	2.00	3.06	4.14	2.6
0.9	7.09	3.69	1.71	334	1.72	2.92	4.27	2.5
1.0	6.80	3.59	1.72	343	1.67	2.96	4.36	2.4
1.1	9.09	3.43	2.03	340	2.70	4.13	5.39	3.9
1.2	11.12	3.24	2.45	354	4.00	6.00	6.3	5.5

Figure 9. PL spectra of pure and incorporated PVP/PVA films.

Figure 10. A schematic diagram of the electronic transitions and emissions of (a) pure and (b) SnS_x incorporated PVP/PVA blends.

Table 3. PL peaks positions of SnS_x incorporated PVP/PVA blends.

Sulfur molar ratio	Maximum peak position (nm)		Peaks positions (nm)
Pure PVP/PVA		427	378(UV), 400(V), 427(V)
0.8		452	381(V), 405(V), 452(B), 485(C), 530(G)
0.9		452	377(UV), 420(V), 452(B), 486(C), 532(G)
1.0		454	390(V), 415(V), 454(B), 487(C), 525(G)
1.1		457	392(V), 417(V), 457(B), 488(C), 520(G)
1.2		462	380(V), 411(V), 462(B), 487(C), 533(G)

Note: UV: ultraviolet; V: violet; C: cyan; B: blue; G: green.