Applied research on 2-6 compound materials for heterojunction solar cells

Several II-VI heterojunctions show promise for photovoltaic conversion of solar energy. The three of greatest interest are p-CdTe/n-CdS, p-CdTe/n-ZnSe, and p-ZnTe/n-CdSe. Several p-CdTe/n-CdS heterojunction cells have been prepared by close spaced transport deposition of p-CdTe on single crystal n-CdS, and by two source vacuum evaporation of n-CdS on single crystal p-CdTe. Both types of cells, in an experimental stage, are quite comparable, exhibiting values of quantum efficiency between 0.5 and 0.9, open circuit voltages between 0.50 and 0.66 V, fill factors between 0.4 and 0.6, and solar efficiencies up to 4 percent. Cells of p-ZnTe/n-CdSe have also been made by close spaced vapor transport deposition of n-CdSe on single crystal p-ZnTe

Mechanism of the photovoltaic effect in 2-4 compounds Progress report, 1 Apr. - 30 Jun. 1969

Photovoltaic effect in group 2-6 compound

Mechanism of the photovoltaic effect in 2-6 compounds Progress report, 1 Oct. 1968 - 31 Mar. 1969

Heat treatment, illumination and darkness effects, and photovoltaic properties of Cu2S-CdS heterojunction

Mechanism of the photovoltaic effect in 2-6 compounds Progress report, 1 Oct. - 31 Dec. 1969

Electronic transitions involved in photocapacitance at Cd2S-CdS heterojunctio

Mechanism of the photovoltaic effect in 2-6 compounds Progress report, 1 Apr. - 30 Sep. 1967

Mechanism for photovoltaic effects in heterojunctions in group 2 to 6 compounds with metallic or quasimetallic barrier layer

Mechanism of the photovoltaic effect in 2-6 compounds Progress report, 1 Oct. 1967 - 31 Mar. 1968

Mechanisms of photovoltaic effects in heterojunctions in group 2 to 6 compounds with metallic or quasimetallic barrier layer

Mechanism of the photovoltaic effect in II-VI compounds Progress report, 1 Jan. - 31 Mar. 1970

Trapped charging and photovoltaic performance of Cu2S-CdS cell including heat treatment effect

Mechanism of the photovoltaic effects in 2-4 compounds Progress report, 1 Apr. - 30 Sep. 1968

Current gain mechanism in copper sulfide-cadmium sulfide diode upon photoexcitation in presence of reverse bia

Radiative pair transitions in p-type ZnSe:Cu crystals

Journal ArticleShallow levels with an ionization energy of 0.012 eV play an important role in the photoelectronic properties of p-type ZnSe:Cu crystals. These levels exhibit the characteristics of the higher-lying member of an imperfection pair involved in luminescence emission, as well as of a trap determining long-time decay rates of luminescence and photoconductivity, and of a center causing low-temperature reduction of free-electron lifetime

Carrier multiplication yields in PbS and PbSe nanocrystals measured by transient photoluminescence

We report here an assessment of carrier multiplication (CM) yields in PbSe and PbS nanocrystals (NCs) by a quantitative analysis of biexciton and exciton dynamics in transient photoluminescence decays. Interest in CM, the generation of more than one electron and hole in a semiconductor after absorption of one photon, has renewed in recent years because of reports suggesting greatly increased efficiencies in nanocrystalline materials compared to the bulk form, in which CM was otherwise too weak to be of consequence in photovoltaic energy conversion devices. In our PbSe and PbS NC samples, however, we estimate using transient photoluminescence that at most 0.25 additional e-h pairs are generated per photon even at energies hv > 5Eg, instead of the much higher values reported in the literature. We argue by comparing NC CM estimates and reported bulk values on an absolute energy basis, which we justify as appropriate on physical grounds, that the data reported thus far are inconclusive with respect to the importance of nanoscale-specific phenomena in the CM process.Comment: 10 pages, 7 figure