Electrically pumped random lasers are realized in ZnO nanocrystallite films in a simple metal–oxide–semiconductor structure. By introducing an i‐ZnO layer, a threshold current of 6.5 mA is obtained. The reported results provide a simple route to electrically pumped random lasing (see figure) with relatively low threshold, a significant step towards the future applications of this kind of laser.

Electrically pumped F–P mode microlasers comprising a single ZnO:Ga microbelt and p-GaN substrate have been realized.

power. [1] X-ray detection technology, as a derivative of its own special properties, plays a key role in multiple applications, including medical radiography, safety surveillance, industrial flaw inspection, and scientific research. [2][3][4] Especially for the global pandemic of Corona Virus Disease 2019, X-ray radiograph and computed tomography scan were employed as rapid and accurate autodetection methods to reveal abnormal lung indications for disease diagnosis. [5] Modern X-ray detectors with the advantages of digital image processing, massive storage capability, data sharing have almost replaced the traditional film-based detectors. Currently, two available schemes were adopted for X-ray detection: direct-detection based on semiconductor materials operating in currentto-current mode, [6][7][8] and indirect-detection based on scintillators working in photonto-current mode. [9][10][11][12][13][14][15][16][17][18] Indirect-detection type X-ray detectors occupy the majority of the market share because of their relatively low-cost and stability. [11,16] As the core component of the detector, scintillator is capable of converting X-ray into ultraviolet (UV)/visible light that can be collected by a sensor array (such as photomultiplier tube, [14] multipixel photon counter, [15] charge-coupled device, [16] and complementary metal-oxide-semiconductor). [17,18] Development over the decades has witnessed the emergence of various scintillators, which were classified according to their own characteristics to fit the demands of different occasions. Yet several issues and limitations still remain. For example, needle-like column CsI (Tl) crystals were commonly used as mainstream products in X-ray imaging applications, due to their large X-ray conversion efficiency, high light yield, and low light-crosstalk. [19,20] Their limitation lies in the high-cost caused by the complicated and time-consuming vacuum fabrication procedures. [21,22] Plastic scintillators, consisting of embedded or coated with scintillation materials, have the advantages of mechanical plasticity, fast decay time, and remarkable radiation resistance. They may seem to be economical alternatives to conventional inorganic scintillation crystals. [23,24] However, they are plagued by relatively low density, weak radioluminescence (RL) emission and poor thermal stability. Since the wide range X-ray imaging technology covers a wide range of applications in the medical, industrial, and scientific research fields. Highly sensitive, flexible, and cost-effective scintillation screens are of great importance for X-ray imaging applications. In this paper, manganese (II) activated 2D butylammonium lead bromide perovskite, namely BA 2 PbBr 4 :Mn (II), is demonstrated as a highly efficient and low-cost X-ray scintillator. The appropriate amount of Mn (II) dopant can act as an activator for achieving the optimization of luminescence performance through efficient energy transfer. This produces a large Stokes shift thus almost eliminates the effect of self-absorption. As ...