For intermediate-band solar cells containing GaAs/InAs quantum dots (QDs), the QD density dependence of the power conversion efficiency (PCE) was theoretically calculated for various sun concentrations under AM1.5 conditions based on detailed balance principles. A QD density of over 5 × 1013 cm−2 was required to achieve a PCE of more than 50% under 10 000 suns. However, under the photo-filled state and 1 sun, the PCE decreased over a wide total QD density range from about 3 × 1010 to 1 × 1013 cm−2. This reduction was attributed to the negative net carrier generation rate through the intermediate band, which was due to insufficient two-step optical absorption. The short-circuit current density increased as the QD density increased up to about 1 × 1011 cm−2 and it then saturated. In contrast, the open-circuit voltage decreased with increasing QD density. This reduction in the open-circuit voltage was suppressed at high sun concentrations.

The potentiometric responses of ion-selective electrodes (ISEs) based on various liquid anion-exchangers for poly(styrenesulfonate)s (PSSs) were examined. The liquid anion-exchangers included lipophilic monoammonium, monophosphonium, diphosphonium, and triphosphonium salts. The molecular weights of PSSs, which had narrow molecular-weight distributions (Mw/Mn < 1.2), were varied from 1.8 × 103 (PSS-1.8K) to 3.5 × 104 (PSS-35K). For PSS-1.8K, ISEs based on diphosphonium salts, polymethylenebis(trioctylphosphonium) dibromides 1—3, exhibited good responses, the response slope and linear response range being −20 to −21 mV/decade and 5.0 × 10−5—5.0 × 10−3equiv dm−3, respectively. As the molecular weight of PSS was increased, the linear response range became smaller, while the response slope was almost constant. Finally, PSS-35K gave almost no response. On the other hand, a wide molecular-weight distribution PSS (Mw/Mn = 3.6) provided a good response, although it had a high average molecular weight (Mw = 1.6 × 104). The selectivity coefficients for PSS over various anions of ISEs, based on diphosphonium and monophosphonium salts, were assessed.