Many thin film heterojunction solar cells contain an interface between the emitter and base which is a very high recombination region and which effectively prevents the passage of minority carriers. However, by utilizing proper design techniques which will be discussed here, the problem can be minimized; efficient thin film heterojunction solar cells can be fabricated, even though they contain ...

The preparation and characterization of heterojunction solar cell with ZnS nanocrystals synthesized by chemical bath deposition method were studied in this work. The ZnS nanocrystals were characterized by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). Lower reflectance spectra were found as the annealing temperature of ZnS film increased on the textured p-...

The effects of germanium tetrabromide addition to tetraphenyl porphyrin zinc (Zn-TPP)/fullerene (C60) bulk heterojunction solar cells were characterized. The light-induced charge separation and charge transfer were investigated by current density and optical absorption. Addition of germanium tetrabromide inserted into active layer of Zn-TPP/C60 as bulk heterojunction had a positive effect on th...

A buried metal heterojunction bipolar transistor with submicron emitter was fabricated by electron-beam lithography. Two tungsten wires of 100 nm width, 100 nm height and 200 nm period were buried in the InP collector layer for the device with an emitter area of 0.3×1.5 μm. Total base-collector capacitance was reduced to about 22% of that calculated from the physical dimensions of conventional ...

The electrical characteristics of InP/In0.24Ga0.76As0.73Sb0.27/In0.53Ga0.47As double heterojunction bipolar transistor (DHBT) are investigated. The study is based on energy balance (EB) transport model and TCAD SILVACO device simulator. InP/In0.24Ga0.76As0.73Sb0.27 DHBT have a low Emitter-Base conduction band discontinuity EC and a minimum base bandgap energy EG among the entire composition ran...

We find that Gd2O3 thin films strongly favor a ( 402) texture growth on a variety of substrates and will form heterojunction diodes with silicon, especially when doped with oxygen vacancies. Even in the thin film limit, these heterojunction diodes appear to be sensitive to gamma radiation, likely from the X-rays created by scattering events, adding to the numerous hurdles that must be overcome ...

Proton degradation was investigated for several types of light-emitting diodes with wavelengths in the near infrared region. All irradiations were done with 50-MeV protons. Several basic light-emitting diode (LED) technologies were compared, including homojunction and double-heterojunction devices. Homojunction LEDs fabricated with amphoteric dopants were far more sensitive to displacement dama...

Substituting olefinic for acetylenic pi-spacers in anthracene-based conjugated semiconductor donors leads to appreciable increases in the power conversion efficiencies of the resulting bulk heterojunction solar cells.

Fermi-level pinning behavior has been observed at the free surface, oxide interface, metal interface, MBE grown surface, stop-regrown homojunction, and misfit-dislocation pinned heterojunction of GaAs. Theories of such behavior are numerous and disparate. Theories of ideal heterojunction band offsets are less diverse, but have still not converged to a single mechanism. Recent studies of heteroj...