Provided is a photothermal conversion layer which transmits visible light, has sufficient infrared-ray absorbing properties, is capable of improving organic electroluminescent element transfer accuracy using laser beam irradiation, and is applicable to a broad range of fields such as electronics, medicine, agriculture, machinery, and the like. Also provided is a donor sheet using said photothermal conversion layer. The provided photothermal conversion layer contains infrared ray-absorbing particles and a binder component. The infrared ray-absorbing particles are composite tungsten oxide fine particles which contain a hexagonal crystal structure. The a axis of the lattice constant of the composite tungsten oxide fine particles is 7.3850-7.4186 ? inclusive, and the c axis thereof is 7.5600-7.6240 ? inclusive. The particle diameter of the composite tungsten oxide fine particles is 100nm or less, and the solar transmittance thereof is 45% or less.