Conformable ${n}$ -Channel Organic Phototransistors With Enhanced Photosensitivity and Broadened Response Range via Insertion of an Alq3 Layer

Organic phototransistors (OPTs) have attrac- ted increasing research interest due to their outstanding advantages in optoelectronic integration and the development of wearable and portable electronics. However, research on
${n}$
-channel OPTs, and particularly,
${n}$
-channel OPTs based on commercialized materials, is limited. In this letter, conformable
${n}$
-channel OPTs are fabricated, which show good adherence onto a curved human eye model. By inserting a tris(8-hydroxyquinoline)aluminum (Alq
₃
) layer, the photosensitivity,
${P}$
, i.e., (
${I}_{\textsf {Light}}-{I}_{\textsf {Dark}})/{I}_{\textsf {Dark}}$
, can be improved by over two orders of magnitude. The changed thickness of Alq
₃
layer introduces the competition between enhanced light absorption and increased carrier trapping/scattering processes, resulting in the optimized Alq
₃
layer at 24 nm for the highest
${P}$
value. Under illumination at a wavelength of 489 nm with a light intensity of 243
$\mu \text{W}$
cm
⁻²
, the average
${P}$
value of N,N1-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13)/Alq
₃
OPTs is over 10
⁵
. This letter provides a method for fabricating conformal high-performance
${n}$
-channel OPTs via the insertion of an Alq
₃
layer.