An imaging element which is formed by sequentially stacking at least an anode, an anode-side buffer layer, a photoelectric conversion layer, and a cathode, in which the anode-side buffer layer includes a material having structural formula ##STR00001##
in which thiophene and carbazole are combined.

A radiation detector includes a first detecting part including a first organic detection layer and a first layer, and a second detecting part including a second organic detection layer. The first layer includes a first material and a first thickness. The second detecting part does not include the first layer. The second detecting part does not include a second layer, or the second detecting part includes the second layer that includes at least one of a second material or a second thickness. The second material is different from the first material. The second thickness is different from the first thickness. The first material includes at least one of a first organic material or a first element. The second material includes at least one of a second organic material or a second element.

A method for producing an organic non-fullerene electron transport compound includes mixing naphthalene-1,4,5,8-tetracarboxylic dianhydride and an amine compound in dimethylformamide. The method also includes heating the mixture to a temperature greater than or equal to 70° and less than or equal to 160° C. for an amount of time greater than or equal to 1 hour and less than or equal to 24 hours. The method further includes isolating an organic non-fullerene electron transport compound reaction product.

An organic photodetector includes a first electrode, a second electrode facing the first electrode, and an activation layer between the first electrode and the second electrode, wherein the activation layer includes a compound represented by Formula 1. An electronic apparatus includes the organic photodetector. In Formula 1, R.sub.1 to R.sub.6 and a3 to a6 are as described in the specification.

##STR00001##

The present disclosure provides methods and compositions for an organic nanofiber-based heterojunction material, comprising nano fibers of an acceptor molecule, the nano fibers coated with a donor molecule, where the acceptor molecule contains a group and the donor molecule contains a companion group, wherein the group and companion group enables strong binding between the acceptor molecule and donor molecule, the strong binding providing for efficient forward electron transfer between the acceptor molecule and donor molecule, and wherein the group and companion group minimize charge carrier recombination between the acceptor molecule and the donor molecule.

Disclosed is an electron transport layer for a flexible perovskite solar cell. The electron transport layer includes transition metal-doped titanium dioxide particles. The titanium dioxide particles are densely packed in the electron transport layer. The electron transport layer is transparent. The use of the electron transport layer enables the fabrication of a flexible perovskite solar cell with high power conversion efficiency. Also disclosed is a flexible perovskite solar cell employing the electron transport layer.

Bandgap-tunable perovskite compositions are provided having the formula CsPb(A.sub.xB.sub.y).sub.3, wherein A and B are each a halogen. The mixed halide perovskite composition has a morphology which suppresses phase segregation to stabilize a tuned bandgap of the mixed halide perovskite composition. For example, the perovskite may be in the form of nanocrystals embedded in a non-perovskite matrix, which, for example, may have the formula Cs.sub.4Pb(A.sub.xB.sub.y).sub.6, wherein A and B are each a halogen. Solar cells and light-emitting diodes comprising the mixed perovskite compositions are also provided.

Sulfur-fused perylene diimides (PDIs) having the formula 2PDI-nS, wherein n is an integer. Such sulfur-fused PDIs (e.g., 2PDI-2S, 2PDI-3S, and 2PDI-4S) are incorporated as electron acceptors in an active region of a bulk heterojunction solar cell and/or as an electron transport layer. Example solar cells exhibit a power conversion efficiency above 5% and a fill factor above 70% (a record high for non-fullerene bulk heterojunction solar cell devices) when 2PDI-nS is used as the electron acceptor. In addition, the solar cells exhibit low open circuit voltage (V.sub.oc) loss.

An imaging element which is formed by sequentially stacking at least an anode, an anode-side buffer layer, a photoelectric conversion layer, and a cathode, in which the anode-side buffer layer includes a material having structural formula

##STR00001##

in which thiophene and carbazole are combined.

The organic small molecule 4,4′,4″,4′″-(5,5-dimethoxycyclopenta-1,3-diene-1,2,3,4-tetrayl)tetrakis(N,N-bis(4-methoxyhenyl)aniline (CPDA 1), shows electrochemical properties very close to spiro-OMeTAD indicating a high compatibility with PSC systems for its use as a hole transport material (HTM). The implementation of the cyclopentadiene dimethyl acetale core helps to red shift the absorption onset of the films as well as provide a flexible spatial configuration of the molecule, which is essential for optimum film forming properties. Transient and steady state emission analysis as well as hole mobility measurements indicate that the new HTM allows a better charge extraction, transport and separation than the spiro-OMeTAD reference compound. PSCs based on the new CPDA 1 show a PCE close to 23% with lower hysteresis than its analogue. Stability studies performed under ambient, heated and humid conditions all showed that CPDA 1 is over-performing spiro-OMeTAD. Furthermore the production cost of CPDA 1 is about 10 times lower than that of spiro-OMeTAD, contributing to render PSCs more affordable.