Because team-based collaboration has become a prevailing mode of production of scientific knowledge, the relationship between division of scientific labor and research performance remains insufficiently understood. Using 148,493 articles from PLoS, we construct the Degree of Division of Scientific Labor (DDoSL) index based on author-contribution statements and the Herfindahl-Hirschman Index (HHI). We use five-year citation counts as a proxy for research performance to examine the association of DDoSL with research performance and explore the moderating roles of multiple proximity dimensions. Research performance is found to be positively associated with DDoSL, and geographical proximity is found to exert a positive moderating effect on the DDoSL-performance relationship. In contrast, social and institutional proximity have no significant association with research performance, and cognitive and organizational proximity do not have any clear moderating effects on the DDoSL-performance relationship. Moreover, positive DDoSL-performance association and positive moderation of geographical proximity are more pronounced in small teams. Overall, the findings suggest that deeper division of scientific labor is associated with higher research performance, while geographic separation may increase coordination costs and attenuate the performance gains from labor division. Thus, small teams may benefit from deepening labor division while minimizing remote collaboration to enhance research performance.