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Nanocrystal (NC) Cu2ZnSnS4(CZTS) solar cells, composed of a nontoxic and earth abundant absorber material, have great potential in low-cost solar energy harvesting. However, CZTS NC films typically must be thermally annealed at elevated temperatures and under harsh environments to produce high-efficiency devices. The efficiencies of unannealed CZTS NC solar cells have been hampered by low open circuit potentials (Voc, <325 mV) and low short circuit current densities (Jsc, <2 mA), primarily because of the incomplete passivation of the crystal surface. Although great progress has been made in understanding the surface chemistry of II–VI and IV–VI semiconductor NCs, the surface chemistry of complex quaternary CZTS NCs is largely unexplored. Here, for the first time, we report a comprehensive study of the surface chemistry of CZTS NCs focusing on depositing ligand-passivated, uniform NC thin films to address the issue of large Vocdeficit and low current collection efficiency typically observed for CZTS NC solar cells. The ligand exchange reactions were rationally designed to target each metal ion on the surface [using both organic L-type ligands such as ethylenediamine and inorganic X-type ligands (I–and S2–)] and to passivate anionic chalcogen sites with inorganic Z-type ligands (ZnCl2). Herein, we show that CZTS/CdS heterojunction NC solar cells made of uniformly passivated CZTS NCs demonstrate a >180 mV improvement in Voc. Furthermore, the influence of device configuration on the collection efficiency of photogenerated carriers in the CZTS NC absorber layer is presented, and the implications of both surface and internal defects in CZTS NCs for photovoltaic performance are discussed.

Postdeposition CdCl2treatment of polycrystalline CdTe is known to increase the photovoltaic device efficiency. However, the precise chemical, structural, and electronic changes that underpin this improvement are still debated. In this study, spectroscopic photoemission electron microscopy was used to spatially map the vacuum level and ionization energy of CdTe films, enabling the identification of electronic structure variations between grains and grain boundaries (GBs). In vacuo preparation and inert transfer of oxide-free CdTe surfaces isolated the separate effects of CdCl2treatment and ambient oxygen exposure. Qualitatively, grain boundaries displayed lower work function and downward band bending relative to grain interiors, but only after air exposure of CdCl2-treated CdTe. Analysis of numerous space charge regions at grain boundaries showed an average depletion width of 290 nm and an average band bending magnitude of 70 meV, corresponding to a GB trap density of 1011cm–2and a net carrier density of 1015cm–3. These results suggest that both CdCl2treatment and oxygen exposure may be independently tuned to enhance the CdTe photovoltaic performance by engineering the interface and bulk electronic structure.

An 800 nm CdSeTe layer was added to the CdTe absorber used in high-efficiency CdTe cells to increase the current and produce an increase in efficiency. The CdSeTe layer employed had a band-gap near 1.41 eV, compared with 1.5 eV for CdTe. This lower band-gap enabled a current density increase from approximately 26 to over 28 mA/cm2. The open-circuit voltage obtained in the high-efficiency CdTe-only device was maintained and the fill-factor remained close to 80%. Improving the short-circuit current density and maintaining the open-circuit voltage lead to device efficiency over 19%. External quantum efficiency implied that about half the current was generated in the CdSeTe layer and half in the CdTe. Cross-sectional STEM and EDS showed good grain structure throughout. Diffusion of Se into the CdTe layer was observed. This is the highest efficiency polycrystalline CdTe photovoltaic device demonstrated by a university or national laboratory.

The article reports on the move by exchange-traded fund (ETF) provider Van Eck Global to launch the index firm Solutions Market Vectors Index. The index firm was formed after Van Eck Global acquired the licensing fee of Market Vectors indices it developed and sold to 4asset Management. The promotion of the firm, including its web site, and Van Eck Global's ETF was already planned to target registered investment advisors.

The article reports that OppenheimerFunds product director Kamal Bhatia has aimed to focus on fixed-income and alternative mutual funds because of the growing demand world wide. Bhatia noted that the investors have already forgotten the mistakes committed by the company in 2008 and are more willing to invest in global strategies than domestic ones. The total global fixed-income fund of the company stood at 8.6 billion U.S. dollars.

The article reports on the plan of exchange-traded funds (ETF) provider BlackRock's iShares to introduce global gold and silver Miners ETFs in 2012. Financial analyst Paul Justice noted that iShares' 455 billion U.S. dollar ETF assets and distribution network would help the company grow the two products. He added that the mining stocks are vulnerable to changes in stock markets because of the high increase in the price of metals.

The article reports on the decision of HSBC Funds to expand its investment products by including a third emerging markets debt mutual fund.

The article announces the decision of Columbia Management to replace Kent Peterson and Kent Bergen as portfolio managers of the company's Columbia LifeGoal Balanced Growth, Growth, Income and Income and Growth funds.

The article reports on the plan of Fifth Third Asset Management to expand its wrap program by including an income fund for registered investment advisors and broker-dealers.

The article reports that a print and online brand campaign will be launched by Deutsche Bank for its db-X brand of exchange-traded funds (ETFs) in 2012. The said currency-hedged ETFs were the first foray of the bank in the U.S. Invesco PowerShares is the distributor of commodity ETFs managed by the bank.

The article reports on the plan of Brookfield Asset Management to launch its first mutual funds in the U.S. on December 1, 2011. According to chief executive officer (CE) Kim Redding, the company is looking to attract 401(k) plans and other retail investors. TS Capital has been signed by Brookfield to work on the registered investment advisor channel.

The article reports that Goldman Sachs Asset Management is planning a focused growth mutual fund in January 2012.

The article announces the appointment of Daniel Greifenkamp as head of mutual fund business development of Brown Brothers Harriman.

The article announces the resignation of Bill Feldmaier as managing director of institutional sales at MassMutual.

The article reports on the plan of iShares to launch the first corporate sector bond exchange traded funds (ETFs) in the market.

The article reports that DAL Investments has listed its first external and internal wholesalers to target advisors.

The article reports on the decision of investors to pull almost 4 billion dollars out of go anywhere bond funds with broad mandates over from August to November 2011. Nadia Papagiannis, analyst at Morningstar, said that uderperformance during market rallies is a common challenge among alternatives funds. She also mentioned that the goal of the go-anywhere funds is to diversify away from traditional fixed-income.

The article announces the appointment of Rich Keri, as head of the global private banking channel to the strategic accounts group of OppenheimerFunds.

The article reports on the move of OppenheimerFunds to add an institutional share class to almost 20 of its mutual funds it considers are best suited for defined contribution plans.