From April 1975 through May 1981, 51 patients had teratoma resected from residual disease following cisplatin-based combination chemotherapy. All patients had normal serum markers before resection of abdominal (25), lung (12), mediastinal (5), thoracoabdominal (8) or other (1) disease. Teratoma was classified as mature in 29 cases, immature in 15 or immature with nongerm cell elements in 7. Of the 51 patients 31 (61 per cent) remain free of recurrent disease, while 20 either had recurrent carcinoma (10) or teratoma (10) requiring further therapy. Nine patients died, including 1 in whom angiosarcoma developed, which was thought to be secondary to previous radiation therapy. In 4 patients the initial relapse of carcinoma developed beyond 2 years after resection. Univariate factors predicting for relapse include tumor burden, immature teratoma with nongerm cell elements and site (mediastinum), while only immature teratoma with nongerm cell elements and site predicted for survival. Patients with immature teratoma had a comparable relapse-free and over-all survival as those with mature teratoma. Using a multivariate analysis, primary tumor site at the mediastinum was the most significant adverse factor predictive for relapse and survival. This study appears to support the various pre-clinical models that demonstrate multipotential capabilities of teratoma. Complete surgical excision of teratoma remains the most effective treatment with continued close followup recommended for high risk patients (immature teratoma with nongerm cell elements, large tumor burden and primary mediastinal tumors) with resected teratoma.

Semiconducting tin sulfide (SnS) was deposited electrochemically from electrolytes containing Sn and S precursors and conditions optimized to maximize its performance as a photoelectrode. Films composed of primarily orthorhombic SnS were electrodeposited on titanium substrates from electrolyte containing 20 mM SnSO 4 and 100 mM Na 2 S 2 O 3 at pH 2.5. For deposition a cathodic pulse of −1.25 V vs Ag/AgCl was applied for 2.75 s followed by a 0.25 s pulse of +0.25 V vs Ag/AgCl repeated for 30−45 min. The films were annealed in argon at 300°C for 3 h. The addition of SbCl 3 (<5%) to the electrolyte gave rise to doping of the SnS film with Sb which resulted in an increase in the photocurrent as well as a switch from p-to n-type semiconducting behavior in an acidified Na 2 S 2 O 3 electrolyte. Incorporation of p-type In into the films from addition of In(NO 3 ) 3 had a smaller effect on the measured photocurrent, and at higher precursor concentration (>5%) the dopants resulted in the formation of secondary phases of Sb and In oxides with reduction in the measured photocurrent. This doped SnS material could potentially be used in systems for the photoelectrochemical production of hydrogen and oxidation of organic wastewater. Density functional theory calculations supported the experimentally observed conductivity increase for photoelectrons as an Sb dopant induced curvature of the valence band. These calculations also provided an explanation to the previous experimental work where Sb doping was used to decrease the resistivity of SnS films. The combination of an automated electrodeposition of an earth abundant metal sulfide with the theoretical calculations to guide the synthesis is an exemplar of how to improve the efficiency of SnS-based solar energy conversion materials. ■ INTRODUCTIONThe economical capture and conversion of solar photons requires materials and structures that are inexpensive and efficient at converting solar photons to electricity or solar fuels. 1,2 A wide range of semiconducting materials, including metal oxides, phosphides, selenides, sulfides, tellurides, and amorphous and crystalline silicon, have been investigated with varying degrees of success. 3 When considering semiconductor materials for a direct solar energy harvesting, two important criteria are (1) the potential for high solar-to-electrical or solar-to-hydrogen conversion efficiency and (2) earth abundance and cost in bulk quantities of the corresponding material components. 3 In addition, it is desired to synthesize these materials using inexpensive and scalable techniques, such as electrodeposition.Certain metal sulfides satisfy both criteria as they have high theoretical solar energy conversion efficiencies (∼24%) and are present in large numbers of minerals. 4 Sulfide-based compound semiconductors have long been the subject of investigation for electronic and optical applications, including FeS 2 , Cu 2 S, Cu 2 ZnSnS 4 (CZTS), RuS 2 , and CuInS 2 . 5−7 Several of these, such as FeS 2 , Cu 2 S, Co, and Cu 2 ZnSnS 4 (CZTS), are comp...

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