A simple solution-phase approach to synthesize high quality ternary AgInSe2 and band gap tunable quaternary AgIn(S1−xSex)2 nanocrystals

Abstract

A facile solution-phase route for the preparation of AgInSe2 nanocrystals was developed by using silver nitrate, indium stearate, and oleylamine-selenium (OAm-Se) as precursors. The evolution process of the AgInSe2 nanocrystals is discussed in detail and different reaction conditions all have a great impact on the growth and morphology of the nanocrystals. Alloyed AgIn(S1-xSex)2 nanocrystals with controlled composition across the entire range (0 ≤ x ≤ 1) was also successfully prepared by modulating the S/Se reactant mole ratio. X-ray diffraction (XRD), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) were used to confirm that the alloyed AgIn(S1-xSex)2 nanocrystals are homogeneous. The UV-vis absorption spectra revealed that the band gap energies of the alloyed AgIn(S1-xSex)2 nanocrystals could be continuously tuned by increasing the Se content.

Independent Composition and Size Control for Highly Luminescent Indium-Rich Silver Indium Selenide Nanocrystals

“…[19][20] Finally, increasing the reactivity of Se precursor by employing weaklycoordinating oleylamine-Se complexes, selenourea, or bis(trimethylsilyl)selenide has been shown to improve composition control over AISe NCs. [21][22][23] Despite this progress, the synthesis of AISe NCs remains underdeveloped, frequently including silver-rich or even binary Ag 2 Se intermediates. 7,18,22 Furthermore, many protocols require growth times of 10 min to few hours to reach target compositions.…”

Shape-controlled synthesis of water-soluble AgInSe2 nanocrystals by a convenient solvothermal approach

“…Fig. 1 shows the XRD patterns of the products synthesized using different volumes of OA, from which we can see that all the samples present similar profiles and all the reflection peaks can be well assigned to the orthorhombic-structure AgInSe 2 with the calculated lattice parameters of a¼ 7.251 Å, b¼8.573 Å and c ¼6.939 Å [11,20,21]. No characteristic peaks of other impurities, such as Ag, Ag 2 Se, In 2 Se 3 or oxides were observed.…”

“…Vittal's group obtained monodisperse orthorhombic AISe nanocrystals by thermal decomposition of a single molecular precursor [11]. Bai et al also developed a solution-phase route for the preparation of AISe nanocrystals [20]. However, these methods are involved in pre-synthesis of complex single-source precursors or the use of toxic and expensive reagents (such as trioctylphosphine, oleylamine) or precursor injection.…”

“…Previously, the studies about AISe were mainly focused on the bulk material and the films due to the limitation of effective synthetic methods [12][13][14][15]. Recently, AISe nanocrystals have been synthesized by serval available methods [11,[16][17][18][19][20][21][22]. Vittal's group obtained monodisperse orthorhombic AISe nanocrystals by thermal decomposition of a single molecular precursor [11].…”

Modulated Binary–Ternary Dual Semiconductor Heterostructures

“…Figure 3a presents atypical HRTEM showing linearly grown tadpole on binary ZnSe.F igure 3b and cp resent the HRTEM of the tadpole part and selected area FFT pattern. Thea nalysis suggests that tadpole growth through diffusion could be possible along either of two identical group of directions on binary ZnSe nanostructures,asshown in Figure 3d.Here,the tadpole AgGaSe 2 can grow either along [1][2][3][4][5][6][7][8][9][10][11][12] or directions,m aking al ine or at an angle of 120 degree with ZnSe.Atomic models showing the possible patterns of growth are further presented in Figure 3e,f.…”