Optical absorption and applications of the ABO4 (A=Ca, Pb and B= Mo, W) semiconductors

Ternary molybdates and tungstates ABO4 (A=Ca, Pb and B= Mo, W) are a group of materials that could be used for a variety of optoelectronic applications. We present a study of the optoelectronic properties based on first-principles using several orbitaldependent one-electron potentials applied to several orbital subspaces. The optical properties are split into chemical-species contributions in order to quantify the microscopic contributions. Furthermore, the effect of using several one-electron potentials and orbital subspaces is analyzed. From the results, the larger contribution to the optical absorption comes from the B-O transitions. The possible use as multi-gap solar cell absorbents is analyzed.

The Death of John the Baptist, [ca. 1761]

Four-page handwritten English composition containing a sketch of the death of John the Baptist beginning "John was imprisoned in the Castle of Machaerus..."

Measures of hall and chapel, [ca. 1800]

This note, likely in the hand of President Willard, directs Mr. [Josiah] Moore and Mr. [John] Walton measure the length, width, and height of the chapel, hall, and library in Harvard Hall. Includes each room's measurements.