This study reports the direct synthesis of WS₂ monolayers with triangular morphologies and strong room-temperature photoluminescence (PL). Unlike bulk WS₂, which does not exhibit PL due to its indirect band gap, the edges of these monolayers show PL signals that are around 25 times stronger than those in the center. Electron diffraction and first-principles calculations reveal that the zigzag edges of the WS₂ monolayers possess metallic edge states, which may be responsible for the enhanced PL. These findings suggest that the structure and composition of the platelet edges play a critical role in the PL enhancement effect. The novel 2D nanoscale light sources could have diverse applications, including the fabrication of flexible, transparent, and low-energy optoelectronic devices.This study reports the direct synthesis of WS₂ monolayers with triangular morphologies and strong room-temperature photoluminescence (PL). Unlike bulk WS₂, which does not exhibit PL due to its indirect band gap, the edges of these monolayers show PL signals that are around 25 times stronger than those in the center. Electron diffraction and first-principles calculations reveal that the zigzag edges of the WS₂ monolayers possess metallic edge states, which may be responsible for the enhanced PL. These findings suggest that the structure and composition of the platelet edges play a critical role in the PL enhancement effect. The novel 2D nanoscale light sources could have diverse applications, including the fabrication of flexible, transparent, and low-energy optoelectronic devices.