Yantara Natalia, Bhaumik Saikat, Yan Fei, Sabba Dharani, Dewi Herlina A, Mathews Nripan, Boix Pablo P, Demir Hilmi Volkan, Mhaisalkar Subodh
Energy Research Institute@NTU (ERI@N), Research TechnoPlaza, X-Frontier Block, Level 5, 50 Nanyang Drive, 637553 Singapore.
LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, Nanyang Technological University , 50 Nanyang Avenue, 639798 Singapore.
J Phys Chem Lett. 2015 Nov 5;6(21):4360-4. doi: 10.1021/acs.jpclett.5b02011. Epub 2015 Oct 20.
Lead-halide perovskites have transcended photovoltaics. Perovskite light-emitting diodes (PeLEDs) emerge as a new field to leverage on these fascinating semiconductors. Here, we report the first use of completely inorganic CsPbBr3 thin films for enhanced light emission through controlled modulation of the trap density by varying the CsBr-PbBr2 precursor concentration. Although pure CsPbBr3 films can be deposited from equimolar CsBr-PbBr2 and CsBr-rich solutions, strikingly narrow emission line (17 nm), accompanied by elongated radiative lifetimes (3.9 ns) and increased photoluminescence quantum yield (16%), was achieved with the latter. This is translated into the enhanced performance of the resulting PeLED devices, with lower turn-on voltage (3 V), narrow electroluminescence spectra (18 nm) and higher electroluminescence intensity (407 Cd/m(2)) achieved from the CsBr-rich solutions.
铅卤化物钙钛矿已超越了光伏领域。钙钛矿发光二极管（PeLEDs）作为利用这些迷人半导体的一个新领域而出现。在此，我们报道了首次使用完全无机的CsPbBr3薄膜，通过改变CsBr - PbBr2前驱体浓度来控制陷阱密度，从而增强发光。尽管纯CsPbBr3薄膜可以从等摩尔的CsBr - PbBr2和富CsBr溶液中沉积，但后者实现了极窄的发射线（17纳米），伴随着延长的辐射寿命（3.9纳秒）和提高的光致发光量子产率（16%）。这转化为所得PeLED器件的性能增强，从富CsBr溶液制备的器件具有更低的开启电压（3伏）、窄的电致发光光谱（18纳米）和更高的电致发光强度（407坎德拉每平方米）。
