Self‐Assembly of Hydrogen‐Bonded Organic Crystals on Arbitrary Surfaces for Efficient Amplified Spontaneous Emission

Organic lasers attract much attention due to their high efficiency, low energy consumption, and structural flexibility. However, long‐term stability and the creation of the lasers on arbitrary surfaces remain a challenge. Here, a synthesis of amide‐based organic molecules that provides packing into hydrogen‐bonded organic crystals (OCs) is reported. The resulting OCs demonstrate an amplified spontaneous emission (ASE) regime with 0.55 μJ cm−2 threshold under the normal conditions due to 5%–13% quantum yield and high emission rate (1.02 ns). The simple process of self‐assembly of the hydrogen‐bonded OCs and highly stable ASE (over 30 min of continuous operation) allow fabricating fibers, flexible polymers, and hard planar periodic optical systems based on them, which paves the way to creating organic laser diodes of an arbitrary design.