Colloidal synthesis of size-confined CsAgCl₂ nanocrystals: implications for electroluminescence applications

Abstract

Because of the non-toxic property and the similar ionic radius to that of Pb2+, silver ion (Ag+)-containing perovskite derivatives have become an important class of Pb-free alternatives that are competitive...

Colloidal Synthesis and Optical Properties of Cs2CuCl4 Nanocrystals

“…Note that the treatment was applied at room temperature, therefore the Ag ions were unlikely to dope inside Cs 2 CuCl 4 NCs. This is also supported by the unchanged PL peak position, demonstrating that no Cu-Ag alloyed NCs were formed [56]. The origin of the bright blue emission of Cs2CuCl4 NCs can be attributed to the Cu ion induced traps.…”

Improving Optoelectronic Properties of Ternary Silver Chlorides via Defect Engineering

“…A positive value of Δ G dec indicates an endothermic reaction, resulting in suppressed decomposition. The Δ G dec values for CsAgCl 2 and Cs 2 AgCl 3 are calculated to be 0.32 and 0.67 eV per formula, respectively, which are significantly larger than the calculated values of hybrid organic–inorganic lead halide perovskite systems, − indicating that the present compounds are very stable, which is in good agreement with the experimental results in previous studies. ,,, …”

“…The ΔG dec values for CsAgCl 2 and Cs 2 AgCl 3 are calculated to be 0.32 and 0.67 eV per formula, respectively, which are significantly larger than the calculated values of hybrid organic−inorganic lead halide perovskite systems, 50−52 indicating that the present compounds are very stable, which is in good agreement with the experimental results in previous studies. 28,29,33,39 Then, the electronic band structures, projected density of states (PDOS) and transition dipole moments are calculated to investigate the electronic properties of CsAgCl 2 and Cs 2 AgCl 3 systems. From the projected electronic band structure of each compound shown in Figure 2a,c, one can see that CsAgCl 2 has an indirect band gap, where the conduction band minimum (CBM) is at the Γ point and the VBM is at the T point.…”

“…Though the ternary silver halides exhibit excellent air stability and tunable light emission properties, it is worth noting that silver­(I) chlorides possess relatively poor luminescence efficiency and low photoluminescence quantum yields (PLQYs). For instance, the PLQYs of Cs 2 AgCl 3 and CsAgCl 2 are less than 20%, which hampers their practical applications. ,,,− However, to date, the underlying mechanism for this limitation is not yet fully understood. For example, previous studies have primarily focused on the excitonic properties of chain Rb 2 AgX 3 ; , nevertheless, the defect physics of these compounds has not been addressed.…”

Thermally Activated Delayed Fluorescence from Perovskite‐Derivative CsAgCl2 Nanocrystals for High‐Resolution X‐Ray Imaging

“…[10,11,13,17,18] Most recently, vacancy-ordered zirconium-based double perovskites are observed to exhibit the strong TADF emission with a 70% PLQY and set off a new wave of research for TADF in perovskites. [16,[19][20][21][22] However, aside from this kind of materials, no other perovskite-type material with TADF emission has been reported by scholars and researchers up to now, which severely limits the understanding of the underlying origin of TADF emission and the relationship between crystal structure and luminescence mechanism in perovskites. Compared with Cs 2 ZrCl 6 (3.23 g cm −1 ), the CsAgCl 2 (4.15 g cm −1 ) has higher crystal density and atomic number, which are conducive to larger X-ray absorption cross-section and larger attenuation coefficient as shown in Figure S1 (Supporting Information).…”