Improved performance of lead phthalocyanine phototransistor by template inducing effect based on optimized-thickness copper phthalocyanine layers

•The performance of PbPc single-layer NIR organic phototransistor was improved with different-thickness CuPc template inducing layers (TILs).•Different-thickness CuPc TILs present different template inducing effects.•2.5-nm CuPc TIL which is quasi-continuous and highly ordered approximate-monolayer produces an optimal template inducing effect.