Yes, it is true that the number of majority carriers available for recombining with excess minority carriers decreases as the excess semiconductor becomes intrinsic. This can be explained by the following points:

1. Excess Minority Carriers: When a semiconductor is doped with impurities, it creates majority and minority carriers. The majority carriers are the ones that are present in larger numbers due to doping, while the minority carriers are present in smaller numbers. In an n-type semiconductor, the majority carriers are electrons and the minority carriers are holes. Similarly, in a p-type semiconductor, the majority carriers are holes and the minority carriers are electrons.

2. Recombination: In a doped semiconductor, recombination occurs when minority carriers (electrons in p-type and holes in n-type) combine with majority carriers. This recombination process leads to the neutralization of these carriers and the generation of heat.

3. Intrinsic Semiconductor: An intrinsic semiconductor is a pure semiconductor with no intentional doping. In this case, the number of majority carriers is equal to the number of minority carriers. This means that there are no excess minority carriers available for recombination.

4. Decrease in Recombination: As the excess semiconductor becomes intrinsic, the number of excess minority carriers decreases. This is because the doping concentration decreases and approaches zero. With fewer excess minority carriers available, the recombination process also decreases.

5. Impact on Device Performance: The decrease in recombination due to the intrinsic nature of the semiconductor has a significant impact on the performance of semiconductor devices. For example, in a diode, the recombination process is responsible for the current flow. As the excess semiconductor becomes intrinsic, the current flow decreases, resulting in a decrease in device performance.

In conclusion, the number of majority carriers available for recombining with excess minority carriers decreases as the excess semiconductor becomes intrinsic. This is due to the decrease in excess minority carriers as the doping concentration decreases, leading to a decrease in the recombination process.