Random laser with intrinsically uncomplicated fabrication processes, high spectral radiance, angle-free emission, and conformal onto freeform surfaces is in principle ideal for a variety of applications, ranging from lighting to identification systems. In this work, a white random laser (White-RL) with high-purity and high-stability is designed, fabricated, and demonstrated via the cost-effective materials (e.g., organic laser dyes) and simple methods (e.g., all-solution process and self-assembled structures). Notably, the wavelength, linewidth, and intensity of White-RL are nearly isotropic, nevertheless hard to be achieved in any conventional laser systems. Dynamically fine-tuning colour over a broad visible range is also feasible by on-chip integration of three free-standing monochromatic laser films with selective pumping scheme and appropriate colour balance. With these schematics, White-RL shows great potential and high application values in high-brightness illumination, full-field imaging, full-colour displays, visible-colour communications, and medical biosensing.

Self-healing technology promises a generation of innovation in cross-cutting subjects ranging from electronic skins, to wearable electronics, to point-of-care biomedical sensing modules. Recently, scientists have successfully pulled off significant advances in self-healing components including sensors, energy devices, transistors, and even integrated circuits. Lasers, one of the most important light sources, integrated with autonomous self-healability should be endowed with more functionalities and opportunities; however, the study of self-healing lasers is absent in all published reports. Here, the soft and self-healable random laser (SSRL) is presented. The SSRL can not only endure extreme external strain but also withstand several cutting/healing test cycles. Particularly, the damaged SSRL enables its functionality to be restored within just few minutes without the need of additional energy, chemical/electrical agents, or other healing stimuli, truly exhibiting a supple yet robust laser prototype. It is believed that SSRL can serve as a vital building block for next-generation laser technology as well as follow-on self-healing optoelectronics.

A demonstration of 2D hole gases in GeSn/Ge heterostructures with a mobility as high as 20 000 cm2 V−1 s−1 is given. Both the Shubnikov–de Haas oscillations and integer quantum Hall effect are observed, indicating high sample quality. The Rashba spin‐orbit coupling (SOC) is investigated via magneto‐transport. Further, a transition from weak localization to weak anti‐localization is observed, which shows the tunability of the SOC strength by gating. The magneto‐transport data are fitted to the Hikami–Larkin–Nagaoka formula. The phase‐coherence and spin‐relaxation times, as well as spin‐splitting energy and Rashba coefficient of the k‐cubic term, are extracted. The analysis reveals that the effects of strain and confinement potential at a high fraction of Sn suppress the Rashba SOC caused by the GeSn/Ge heterostructures.

Printing technology has led to a multitude of revolutions in design, conception, fabrication, and application of optoelectronics nowadays especially for wearables and one‐off devices. Recent advances range from solar cells, batteries, sensors, LEDs, displays, biomedical widgets to smart tags. Inkjet‐printed random lasers (IPRLs), demonstrated here, fill in the crucial but missing piece of the puzzle in printed optoelectronics as well as progress in laser research. A broad emission spectrum of IPRL inks covering more than 75% gamut of CIE color space is successfully exploited and well adopted by commercial desktop inkjet printers. Furthermore, based on the digital, ink‐efficient, mask‐free patterning, and drop‐on‐demand printing technique, a series of long‐anticipated proofs‐of‐concept including on‐chip laser lighting modules, red‐yellow‐green‐blue pixel‐based laser displays, and ink‐crypto/laser‐coded security printing technique are also demonstrated.

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