Organic semiconducting
single crystals are ideal building blocks
for organic field-effect transistors (OFETs) and organic photodetectors
(OPDs) because they can potentially exhibit the best charge transport
and photoelectric properties in organic materials. Nevertheless, it
is usual for single-crystal OFETs to be built from one kind of organic
material in which the dominant transport is either electron or hole;
such OFETs show unipolar charge transport. Furthermore, single-crystal
OPDs present high performance only in restricted regions because of
the limited absorption of one-component single crystals. In an ideal
situation, devices which comprise both electron- and hole-transporting
single crystals with complementary absorptions, such as single-crystalline
p–n heterojunctions (SCHJs), can permit broadband photoresponse
and ambipolar charge transport. In this paper, a solution-processing
crystallization strategy to prepare an SCHJ composed of C60 and 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-PEN) was shown.
These SCHJs demonstrated ambipolar charge-transport characteristics
in OFETs with a balanced performance of 2.9 cm2 V–1 s–1 for electron mobility and 2.7 cm2 V–1 s–1 for hole mobility. This
demonstration is the first of single-crystal OFETs in which both electron
and hole mobilities were over 2.5 cm2 V–1 s–1. OPDs fabricated upon as-prepared SCHJs exhibited
highly sensitive photoconductive properties ranging from ultraviolet
to visible and further to near-infrared regions as a result of complementary
absorption between C60 and TIPS-PEN, thereby attaining
photoresponsivities that are among the highest reported values within
the OPDs. This work would provide valuable references for developing
novel SCHJ systems to achieve significant progress in high-performance
ambipolar OFETs and broadband OPDs